cardo324

From what I can tell it looks good. However I have no experience with this machine and have no idea if it can handle the cooling requirements. Price is good on it though.

I opted for building a rack and using rackmount cases since I was going to have quite a bit of equipment. The bottom server is an old HP and is extremely loud, but I never run it, its primarily there because it wouldn't sell for much money so I may as well keep it. Everything else is dead silent.
 
If I want to swap hard drives I have hotswaps in the front for most of my drives, any maintenance can be done by pulling them out on the rails, and I have a pull out KVM so I don't need to drag a monitor keyboard and mouse if I have issues that can't be solved remotely. Everything is MUCH easier than if I was to build in cases.
 
When I move to a new house all I have to do is take the top 24 port patch panel out of the rack, screw it to the wall in the closet, and load the entire unit into the trailer. It is on a rolling cabinet and fits right back into the closet.
 
I don't have any recent pictures, but here is from when I was first assembling it:
 

 
If you do go with a rackmount setup, DO NOT buy Norco cases, I bought two different models and neither of them fit the rack with rails attached. Apparently its random whether you get one built to the correct dimensions or not as there are tons of complaints online about it. I already had one system completely built and running in the case, so I had to notch out 1/4" of my rack on each side to make it fit.

The 970 is the higher value card.  It's essentially 80% of a 980 for 60% of the cost.  Both overclock a solid 15-20% over their stock speeds.  
 
It really depends what you want to do with them.  If you're running 1080p either will last you just as long as the other, there's not going to be a huge difference.  980 SLI will hold up better down the road though.
 
If you have the money, the 980 makes more sense since you don't want to upgrade for a few years.  It has slightly longer legs, but quite frankly if you get to the point where a 970 isn't satisfactory I doubt a 980 will be much better.
 
 

Did you skip the Phantom 530 for a reason?  You listed the 630, and the 410, but the 530 sits between the two.  It's a good solid option.  If you are looking at only the 630 or 410 because of reasons your own, go with the 630.  

The difference is not much, the 980 has a performance advantage and it has complete full speed memory while on the 970 the last .5 is slower. The 980 is A LOT more costly but if you want 4k it might be worth it.

The 980 FTW edition.
 
And the AIO doesn't cool the other ICs on the boards.

I would wait with that 4k monitors till they get more affordable. And even 2 GTX 980 probably wont be enough for 4k@stable 60fps on one monitor. Depends on the game though.
 
Edit: And I dont think that these 2 cards will really last 4-5 years unless you want to turn the settings down

just look at videos and see for your self