NZXT started selling a bracket, Kraken g10, that lets you use most Asetek AIO coolers.
https://www.nzxt.com/product/detail/138-kraken-g10-gpu-bracket.html
Whether that is good for R9 290X, I do not know. I wouldn't think it would help much over regular aftermarket non-reference cooler. The...
If you go x58, you may consider a cheap Xeon. I snagged a 32nm 4c/8t Xeon E5640 for cheap, and its been great, OCs well, and slightly lower power consumption vs the 45nm i7s.
A FX 8350 OC'd will not bottleneck any single GPU. Only time you would start to see less performance than you should out of the GPU with that CPU is if you throw two or three GPUs in there.
Best card for the price / performance to me is the R9 270, I've seen them new for $160-180 w/ 2 free...
Exactly what I thought when I read the OP.
I would say two years is a safe bet, could possibly stretch it to three depending on how the "next-gen" ports are, thus far they haven't been anything special.
I guess a budget would help. For under $250 the 280X (7970) is still a great card for the price used these days. If you want a card under $200 the r9 270 is pretty nice once OCd for 1080p.
Either way you can't go wrong really. If you do go the r9 290X/290 route, make sure you get one with an aftermarket cooler unless you plan on watercooling.