Building a new system. Need help with config

ok I'm thinking about getting a new system.
Will be running VMware (3~4 servers together).
Just bought 2 monitors (samsung xl20 / dell 2407fpw rev 4), so bit tight on budget.
here's what I got so far.

Q9300
orsair performance 800 4gb (2gb X 2) (might get 8gb)
Seagate SATA 750Gb
Asus P5K-1394
Cooler master extream 650W
Sonata RS100 full tower
Gbyte 512Mb 8600GT
ODD (DVD writer comber)

And here's my question.
1) P5K or DS3? which one's more stable with Q9300?
2) Should i go for 8 gb ram? will be running 4 x win2k3 and 1 x win2k8 on VMware
3) Coller master extream PSU is it ok? willing to spend up to $50 more on PSU
any recommendation?
4) Should i go for 2 x 500gb HDD?

Thanks in advance for your help.