It's a huge card, I can tell you that! I installed it on a similar case the other day and had to remove the whole Hard Drive rail. Had to put the Hard Drive in a 3.5" Media Card Reader/Floppy spot. It worked great though. The great thing is that those cards cool so well! Perfect exhaust system!
Yes. The 5970 will fit in the current iteration of the FT02 case, but you do have to remove the grill from the center fan unit. But pleased be advised that this glitch has been taken notice of by Silverstone and fixed by way of the RV02-E chassis, wherein there are new 180mm AP fans whose "grills" fit flush the top of the fans, thus allowing for a 5790 to be installed. If you want to learn more please see the following link:
Remember that the RV02 and the FT02 are pretty much the same chassis. So with the RV02-E you're pretty much seeing the what the FT02 will be eventually. Eventually is a relative term, of course. Also remember that the performance of the 5970 does come at a price, literally, as well as with regard to heat, noise and size, though compared with, say, 5850s or 5870s in Crossfire it may be "better". A good place to look is this site, Tomshardware.com. They have been running a series entitled "Building a balanced gaming PC". It really is quite informative. In addition, they have individual reviews of the the 5870 and 5970, and also the Crossfired 5850s. Just make sure that you have enough ventilation and and power supply for these things.
Also be advised that there is a FT02 case that corrects the fan problem as of now. Silverstone has introduced a "special edition" version with a red painted interior. Esthetics aside, this unit includes the aforementioned fan change as well. I don't know when the fan change will be incorporated in all the FT02s and the RV02s, but common sense would indicate that it would be fairly soon. Indeed, I have been in contact with the company's Calif. office in the hope of ascertaining just when. I hope that this helps.
I was able to fit a Quadro Fx 5600 in the FT02. I was a little worried about leaving the fan grill off but was able to mod the spacer between the fan and case with ease.So that I could leave the grill on. The filter is still accessible and functional but needed the tab (used to slide in or out)to be trimmed a bit also. I'm not sure if the 5970 is bigger than the Quadro but I think most cards will go in this case with some trimming of the fan bracket/spacer. Those new fans look like they would also do the trick!