The question I would like specifically answered are:
1. Will the CPU bottleneck the GPUS to a point where my plan cannot be achieved (less than 60fps on max settings), and if so what overclock would solve the problem?
2. PSU and case, will the RM1000 supplied cable fit the case or are extensions required (specific yes or no from only users who had tried the same parts)?
3.What is the best airflow setup for the case, my current plan is to have 2x fron t 140mm fans intake and 1x 140mm fan at back and the h100i radiator with 4 fan push/pull at the top exhaust?
1. It shouldn't
2. NA (I haven't used either part so I won't answer per your request)
3. That's a typical set up, so nothing wrong with it. I would also consider making the rear an intake as well and have the 4 fan CPU cooler be your only exhaust.
My gaming needs are simple, the latest and greatest games, running on that single monitor at 1920x1080 at maximum setting (MSAA 8x and 200% resolution on BF4 for example) at a minimum of 60FPS flat. The build must be able to do this for at least 5 years and be able to accommodate possible future monitor additions.
Using 2x r9 290X in CF should easily handle the 1080 graphics requirements you want. My only comment is in regards to your 5 year statement. For technology, 5 years is a lifetime and anything you buy today will probably not be able to meet the graphical demands of 5 years from now. 3 years...? Probably; 5 years...? Probably not.
To give you some perspective, here's a comparison of the r9 290X vs 5870
(the 5870 was top of the line about 5 years ago). These are single cards, so to emulate Crossfire, take any of the 5870 scores and multiply by 1.8 or 1.9. You should notice that none (or very few) will achieve 60 fps.
When people ask me, I recommend (instead of spending $1000 now) they spend $500 now knowing full well they will buy a replacement GPU in about 3 years for $500. Final cost is the same, but you benefit from the newest technology twice, as opposed to just once.
Hope this helps.