If your worried about space, the CM690-II Advanced is more than capable of supporting an SLI setup.
Haven't checked the mobo section on here for awhile, but last time I did there was still people having problem with Asus boards despite bios updates.
Seeing as you have quite a big budget, I'd swap the H70 for either the Noctua NH-D14, or the Thermalright Silver Arrow. Would need a big case though to fit one of those in though.
You could also save a few £'s by swapping the RAM for either the XMS3 or the Geil. Slighty slower RAM but I doubt there's any real noticeble difference between 1600MHz and 1866Mhz (I could be wrong though)