so i basically am deciding on this almost exactly except a few things. I went with a 430w psu because the quadro and firepro cards barily sip power. and i got 1333 memory instead. shouldn't be much a diff between the 1333 and 1600.
You're definitely right about the RAM - not much of a difference. But the 430W PSU should be fine, I think I overestimated the power requirements.