1.5GB RAM config

Hello,

I am planing to get 1.5GB of RAM for my ASUS A8V mobo.
Since I already have a pair of matched OCZ 2x512MB PC3500 (2.5-3-3-7)
RAM I was planing to get another one of these modules but it seems
OCZ sells these only in pairs and I don't need 2GB.
Now, I was planing to add an OCZ 512MB PC3200 (2-3-2-5) module,
would this work?

While this module in PC3200, as opposed to PC3500, its timings are
better(part of the more expensive "enhanced latency OCZ series") so
I was thinking they are about the same in reality?

Thanks.