You can run any combo of hardware you want, you just have to figure out what class. And if you want to run a second rig, it has to be different hardware than the first rig. I actually think this is the first year that they have used the point handicap for class restrictions. Before iirc, it was similar (# of cpu threads, gpus, cooling), but not as specific.
i7+295+water: 8+2+1 = 11. Yep you are correct.
You could run your 8800gt, but it would be in place of the 295. Or you could run it in a second rig.