I think that it is well worth getting 2 GB of ram rather than 1.
I have an asus board, havent tried OCZ, but i got a pair of 1 GB G.skills for about the same price as some of the OCZ ones and it has not messed up yet. Plugged it in and not problems. Hope that helps some.
If i were you, i would save some money and get a less expensive video card so you can save some pocket change for then the DX10 gets released. Maybe a 7600 for now to get that extra 1GB of ram?