if apil sa imo plan ang to upgrade processor in the near future, then getting that MSi R6850 Cyclone PE would be a good option right now even with ur current setup
after that videocard upgrade if u still have the budget, sell your mobo,procie,mem(if its DDR2) and get a sandybridge system. that way its more of a future proof thans staying wth an old lga775
imho