May i say you won't run anything at all ?!!
Why ? ---> Because i don't see any hard disk :rotfl:
More serious, it seem it's a very good rig you will have
Howewer, may i suggest one thing or two :
Do you really need quad-core ?
SH4 will be happy with just two cores, and more important : with the new intel core2 duo, (E8400 @ 3ghz, 6 Megs Cache, for exemple), the cpu will perform better than Q6600 in all apps which is not massively multi-threaded. And i think the E8400 is cheaper.
For the graphic card :
Well, same thing : Do you really need SLI ? SH4 will be ok with only one ; And with the bucks, you can order a more powerfull one.
But it's up to you ; You do what you want with your money