It's pretty much similar to mine, except I have 8Gig RAM and a 8600GT instead of the 8800.

Poser 7 will run just fine on that but if you can afford it I'd go for more RAM, you could maybe offset it by dropping the 8800 to an 8600 as Poser doesn't utilize the extras on the 8800 and the 8600 is still DX10 compliant for your gaming!

Injustice will be avenged.
Cofiwch Dryweryn.