You need a serious powerful PC in order to do graphic intesive computing. What you can do is have a list of peripherals ready before you call DELL or HP or Gateway, etc. to put a system toghether for you.
You might want:
.A 250 Mega Byte, 7200R RPM, 8 Meg Buffer harddisk from Western Digital, Maxtor, or Seagate
.A Video car 250MB Video card: Either an ATI
Radeon X850 XT Video Card, PCIe, 256MB GDDR3
or an NVidia GeForce 7800GTX, 256 Meg of Memory
.An AMD 64 Athlon, 3400+ processor
1 Gigabyte or more of fast system memory
Other peripherals such as sound cards and network interface cards are optional and the vendor will match your system with a good set of such peripherals.