DariusHG

1. Depends on the screen, but it will look worse than a 1080p screen(unless you have a crt). Id probably just get a 1080p screen if you don't watch 4k stuff often.
 
2. Normally, depends on the actual screen.
Changing the res on the screen to 1080 won't make it any better.

If you manually downscale a TV it is the same as playing a 1080p video on a 4K screen. It should still be crisp, if your TV isn't too big.

I've started seeing this guide recently spring up from the PCMasterRace subreddit: http://i.imgur.com/tgrbCnr.jpg
 
And honestly, it really needs some editing, and needs to be a version that's not set in stone like that image but rather a thread. And I'm bored. So here we go:
 
Tier 1
Antec - High Current Pro, High Current Platinum
Be Quiet - Dark Power Pro P10, Dark Power Pro 11
Corsair - AX, AXi, HXi
Enermax - Platimax
EVGA - G2, P2, PS
Fractal - Newton R3
LEPA - G1600
Seasonic - X, Platinum, Snow Silent
Super Flower - Leadex
XFX - Pro Gold, Pro Black
 
Tier 2
Antec - EDGE, TruePower Classic
Cooler Master - V-series (fully modular)
Corsair - RMi, HX
EVGA - GS, GQ
Fractal - Edison M
Seasonic - S12G, G XFX - TS Gold, Pro XXX, XTR
 
Tier 3
Antec - High Current Gamer, Neo ECO
Be Quiet - Straight Power E9, E10
Corsair - RM (variations apply)
Cooler Master - VSM ("V-series" Semi modular)
EVGA - B2
Fractal - Tesla R2
OCZ*1 - ZX
PC Power & Cooling*1 - Silencer Mk III, Turbo Cool*2
Rosewill - Capstone, Lightning, Silent Night, Tahyon, Fortress
Seasonic - M12II, M12II EVO, S12II
Silverstone - Gold SFX, Gold Evolution, Strider Gold
Super Flower - Golden Green
Thermaltake - DPS Gold
XFX - Core, ProSeries Bronze, TS Bronze
 
Tier 4
Antec - EarthWatts/EA Green
Corsair - CS
Cooler Master - GM
EVGA - 1000G
FSP - Aurum Pro
Be Quiet - Power Zone
Enermax - Revolution X't
Silverstone - Strider Plus
 
Tier 5
Antec - Basiq VP-F, Basiq BP, EarthWatts Platinum
Enermax - NaXn 82+
Fractal - Integra M
NZXT - Hale90 V2 OCZ*1 - ZT, ModXStream
Silverstone - Bronze SFX
Thermaltake - ToughPower Gold
 
Tier 6
Antec - Basiq VP
Be Quiet - Dark Power Pro, Pure Power L8, Straight Power E9
Bitfenix - Fury
Corsair - CX
EVGA - 500/600 B, NEX-B (B1), NEX-G (G1)
FSP - Aurum, Raider Silver
Fractal - Integra R2, Tesla R2
NZXT - Hale82 V2 OCZ*1 - Fatal1ty
Rosewill - Hive, ARC (M)
Silverstone - Strider Essential
Thermaltake - LitePower, London, ToughPower
Zalman - GS/GT
 
Tier 7
Cooler Master - Elite series
Corsair - VS
EVGA - 430/500W 80+ (W1)
ThermalTake - Smart Bronze, TR2-RX
 
Ones to stay away from (NOT a conclusive list)
Any shitty-brand PSU like Apevia, Logisys, Diablotek, etc
Generic Chinese units
Cooler Master - Thunder
EVGA - 400W
FSP - Raider Bronze
Thermaltake - TR2, PurePower
 
(I don't know why this section comes out double spaced, it doesn't show up as so in the editor)
 
Footnotes
*1 - OCZ and PC Power & Cooling now known as FirePower
*2 - Regarding 860W model, other Turbo Cool models were different and are no longer in production under the FirePower name
 
Idk conclusion? 
General advice? Pick a good PSU for your system and let it last. Choose one from a good OEM, one that's known for being high quality, and is as high up on this list as you can get for your budget. Balance out your builds and don't pick flagship components like CPU and GPU combined with a tier 6 PSU. People don't hate on the Corsair CX because it's a CX, but because people are pairing it with OC'd i7s and two flagship GPUs and wonder why they break.

Sapphire is the best when it comes to AMD, ASUS cards are poorly designed.

There's not a whole load of 2560x1080 benchmarks around, so it's hard to compare really. 
 
I'd suggest taking a look at 1080p and 1440p benchmarks, then 2560x1080p should be around in the middle of those, leaning more towards 1080p.

At 1080p get the gtx 970. Performs slightly faster (at 1080p), overclocks much better, uses less power and runs cooler. Chart shows that the 970 at 1080p is as fast as a stock 390x. A 390 is about 10% slower than the 390x. Edit: found a graph using the 390.

OP you can always go for a Xeon 1231 v3. It's the same as a 4790k but $100 USD cheaper because it's locked at 3.4Ghz. It still has all the features of an i7. This is just if you feel like capping out your budget isn't the best idea. Getting the 1231 v3 will save you a little. And since it's locked, you won't have to spend extra money on the best motherboard or CPU Cooler. You can devote more of that money to more storage or maybe more RAM if you get serious about production. *sorry if someone already suggested the Xeon

the 290 isnt THAT inefficient, but a 970 would be more efficient

Cool one!
 
this one is a beast!

k version allows for an overclock, and it does make a difference
 
and as seen here:
 
http://pcpartpicker.com/p/RLFbQ7
 
a 980 does fit the budget (if it is too much swap the h100i for a 212 evo)

PCPartPicker part list / Price breakdown by merchant
 
CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor  ($232.99 @ SuperBiiz) 
CPU Cooler: Cooler Master Hyper TX3 54.8 CFM Sleeve Bearing CPU Cooler  ($19.99 @ NCIX US) 
Motherboard: Asus Z97-E ATX LGA1150 Motherboard  ($99.99 @ SuperBiiz) 
Memory: PNY XLR8 16GB (2 x 8GB) DDR3-1600 Memory  ($91.46 @ Amazon) 
Storage: Samsung 850 EVO-Series 120GB 2.5" Solid State Drive  ($69.98 @ OutletPC) 
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive  ($48.75 @ OutletPC) 
Video Card: EVGA GeForce GTX 970 4GB Superclocked ACX 2.0 Video Card  ($334.99 @ Micro Center) 
Case: Corsair 100R ATX Mid Tower Case  ($47.99 @ Micro Center) 
Power Supply: EVGA SuperNOVA GS 550W 80+ Gold Certified Fully-Modular ATX Power Supply  ($59.99 @ NCIX US) 
Total: $1006.13
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-06-16 12:49 EDT-0400
 
You should order the parts in the US, they are cheaper

What about your English?
I didn't notice anything wrong with it..

I am terrible with girls and asking them out, after 2 relationships, my third and current couple was the one who asked me out. It can sound like a topic but, just be yourself, because if you try to be someone you're not... you'll end up burnout.
And please, just please. No cheesy stuff hahaha

1. High school student 
2. French , basic computer programs , Biology , Math and of course Physics and Chemistry , an instrument ( Maybe a guitar ) , basic self-defense technique , ... 
3. A Developer/researcher for Bio-Nano technology ... 

Sure!
 
1) Student, hopefully getting an apprenticeship in something technological at age 16. I also work for my father.
 
2) Slowly learning some coding, largely just watching YouTube and browing LTT forum to become more knowledgeable in hardware. I'm also largely involved in a youth folk band playing violin and I've recently picked up saxophone, so I have that going for me.
 
3) Create my own small business, doing something with computers. or become an author, because it runs in the family.