hi guyz, am about to build a new PC was considering the following hardware spec:

i7 processor (2.66ghz)
285 geforce vga
6gb ram
X58 mobo
1k watt PSU
windows Vista (not sure which one , hence i seek a help here )
ummm for the rest of pieces ill go with default in market, my main concern is stability and performance
what should i expect smooth 5 boxing with high quality visuals? or some tweaking necesarry?
and if someone might be wondering why not the 295, heared it have some stability issues in wow

thanks again