Ciano

I say my first "true" SLI gaming rig because I currently have a GTX 690. Here are the specs of the new PC:
 
http://pcpartpicker.com/user/Seegs108/saved/WG88TW
 
Intel Core i7-5930K 3.5GHz 6-Core Processor   Corsair H110 94.0 CFM Liquid CPU Cooler   Asus X99-DELUXE ATX LGA2011-3 Motherboard   Corsair Vengeance LPX 16GB (4 x 4GB) DDR4-2666 Memory   Samsung 840 EVO 1TB 2.5" Solid State Drive   2X GeForce GTX 980 4GB "Reference" Video Card (2-Way SLI) (One Asus and One Gigabyte due to in-stock limitations)   nVidia Branded LED 2-Way SLI Bridge   Corsair 750D ATX Full Tower Case   Corsair RM 1000W 80+ Gold Certified Fully-Modular ATX Power Supply   LG 34UM95 60Hz 34.0" Monitor        Previously owned Peripherals:   Razer DeathAdder Black Edition Logitech G710+ Mechanical Keyboard Swan M10 2.1 Desktop Speakers Ikea Jerker Desk 32TB Worth of 3.5" Hard Drives (15 total) V-Moda Crossfade LP's (Phantom Chrome) Ratpadz XT Mouse Pad XTrakPads Ripper XXL Desk Pad Sans Digital TowerRAID TR8M+B - 8 Bay RAID Tower   Let the fun begin:         FINISHED PHOTOS:   Side Panel Off:       Side Panel On:         The Rats Nest (Yes, the panel fits with no bend or buldge...somehow )    

No problem. Luckily, SSDs can be ghetto mounted without any issues I've finally gotten round to planning an actual mounting solution for my new ones. Little mod idea here

Well...you try your best mate so I wouldn't worry about it. There are some people on here who are just lazy with their english when they can speak it really well. You on the other hand can't help it. I think you're doing a great job despite your condition. Good on ya!

Well, you don't need to go with ZFS, you could just use the normal UFS:
source: FreeNAS docs#RAM
Also, while ECC memory is recommended, problems when using non-ECC
memory need not necessarily arise. Sure, the data integrity checks of ZFS
will be rendered rather pointless, but that doesn't make ZFS useless, it just
reduces its data integrity features to those of pretty much every other file
system which doesn't have them in the first place.
 
source: FreeNAS docs#RAM
Don't get me wrong, I definitely recommend using ECC with ZFS (after all,
my new server will have ECC RAM exactly for this reason),but it's not an
absolute and unconditional necessity if you're really strapped for cash,
although as said, UFS might be the more reasonable choice in that case.
 
source: FreeNAS docs#RAM
ZFS does work with less RAM. I've been using a system with 4 GB or RAM and
a 17 TB raw/12 TB usable capacity pool since last summer and it works just
fine (although it's Linux with ZFS on Linux instead of FreeNAS, if FreeNAS differs
in this, feel free to correct me). More would be preferable, but as long as my
sytem doesn't do much else it's adequate (if something else on the system
starts hogging RAM though, write performance for my pool drops noticeably).
In general I'd say it's important to distingiush between recommendations
(RAM >= 8GB, ECC) and what you can get away with if your budget is really
restricted, if necessary by using UFS instead of ZFS (which would probably
be my personal recommendation if ECC is out of the question).
@Ciano : It would be helpful to know exactly what hardware you have,
how much storage you need, what the purpose of the NAS will be (backup,
media server, general storage or w/e ) and so on. It's a bit tricky to
give adequate advice when we're in the dark.
Also, since your system is from 2002, it might not be a stupid idea to
abandon it and go for a prebuilt NAS IMHO. Sure, getting the maximum
life span out of old components is nice and all, but old components are
far more likely to fail than newer ones (yeah, I know it's obvious, but
it's also important to keep in mind), and the power consumption of a
newer NAS will very likely be quite a bit less. Not that you need to,
but I'd say it's at least worth a thought or two.

PCPartPicker part list / Price breakdown by merchant / Benchmarks
 
CPU:  AMD FX-8320 3.5GHz 8-Core Processor  ($129.99 @ Amazon) 
CPU Cooler:  Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler  ($29.99 @ Microcenter) 
Motherboard:  MSI 990FXA-GD65V2 ATX AM3+ Motherboard  ($129.99 @ Newegg) 
Memory:  Crucial Ballistix Sport 16GB (2 x 8GB) DDR3-1333 Memory  ($119.99 @ Newegg) 
Storage:  Samsung 840 EVO 120GB 2.5" Solid State Disk  ($89.99 @ Amazon) 
Storage:  Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive  ($59.99 @ NCIX US) 
Video Card:  Gigabyte GeForce GTX 780 3GB Video Card  ($499.99 @ Amazon) 
Case:  Fractal Design Arc Midi R2 (Black) ATX Mid Tower Case  ($79.99 @ Newegg) 
Power Supply:  Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply  ($69.99 @ Newegg) 
Total: $1209.91
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-29 15:57 EST-0500)

PCPartPicker part list: http://pcpartpicker.com/p/2sfwf Price breakdown by merchant: http://pcpartpicker.com/p/2sfwf/by_merchant/ Benchmarks: http://pcpartpicker.com/p/2sfwf/benchmarks/   CPU: Intel Core i7-4770K 3.5GHz Quad-Core Processor  ($299.99 @ Newegg)  CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler  ($29.98 @ OutletPC)  Motherboard: Asus Z87-PLUS ATX LGA1150 Motherboard  ($158.99 @ SuperBiiz)  Memory: A-Data XPG Gaming Series 8GB (2 x 4GB) DDR3-1600 Memory  ($62.99 @ Newegg)  Storage: Samsung 840 EVO 120GB 2.5" Solid State Disk  ($97.99 @ Amazon)  Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($82.94 @ Amazon)  Video Card: Gigabyte Radeon R9 280X 3GB Video Card  ($355.98 @ SuperBiiz)  Case: Fractal Design Arc Midi R2 (Black) ATX Mid Tower Case  ($79.99 @ Newegg)  Power Supply: Corsair CX 500W 80+ Bronze Certified Semi-Modular ATX Power Supply  ($59.99 @ Microcenter)  Total: $1217.84 (Prices include shipping, taxes, and discounts when available.) (Generated by PCPartPicker 2013-12-29 15:32 EST-0500)  

You want to get 16BG of RAM and a 2GB graphics card. You will only need a 500W PSU and won't need an aftermarket CPU cooler.
Now someone else come along and give him a parts list

PCPartPicker part list / Price breakdown by merchant / Benchmarks
CPU: AMD FX-8320 3.5GHz 8-Core Processor ($129.99 @ Newegg)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: Gigabyte GA-990FXA-UD3 ATX AM3+ Motherboard ($132.98 @ OutletPC)
Memory: G.Skill Sniper 8GB (2 x 4GB) DDR3-1600 Memory ($81.49 @ OutletPC)
Storage: Samsung 840 EVO 120GB 2.5" Solid State Disk ($97.99 @ Mac Mall)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($74.97 @ OutletPC)
Video Card: MSI GeForce GTX 780 3GB Video Card ($499.99 @ NCIX US)
Case: Fractal Design Arc Midi R2 (Black) ATX Mid Tower Case ($79.99 @ NCIX US)
Power Supply: Corsair CX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($79.99 @ Microcenter)
Total: $1207.37
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-29 15:27 EST-0500)