I'm about to build a new shuttle system (XPC SB75G2 V2) and I would like to go with either the X800 pro or the 6800 video card. My question is for any users with a similar pc and either of those two cards. I'd just like to know if you have any heating issues, does it fit and what you can do to keep the heat down, etc. because I'm pretty sure that I'm going to go with this type of system. Any kind of help would be great, thanks 