It's six of one, half a dozen of the other!
If you are going to be gaming, then the 2nd one would probably be a better bet as the GF8800 is a much better card than the GF8600.
The RAID 0 setup on the first computer is good for gaming too, but you could always buy a 2nd hard drive and run RAID 0 then.
2nd one wins with giving you a proper Win Vista CD. If the licence is a full one (not an OEM one) then that'll be useful in the future.
Personally, after mulling it over, I would go for the second one and add a large hard drive for extra storage.