Hey
As far as GPU's go you may like to consider the following:
NVidia 4 Ti 4600 - probably the best value for money card. Will do the job and is not too expensive - you could then save up for something better ?
NVidia Quadro 4
Something like the 750 XGL represents good value for money if you have the cash. ie its bigger brother the 900 XGL doesn't give too much more performance increase - well some but the price doesn't justify the 900 over the 750 in my case - unless you can persuade a mate to buy you one..., but a step above the 4 Ti 4600.
Apart from that you could look at the ATI cards but I dont know much about those.
nvidia 4 Ti4600 -