I believe the SDR card would be a bit faster/better. I'm pretty sure that the Radeon 7000 uses DDR memory on a 64-bit bus and SDR memory on a 128-bit bus (nVidia did this also with the original MX chip), so although the memory is DDR vs SDR there is no performance difference in the RAM (166 MHz DDR (DDR 333) with 64-bit bus = 166 MHz SDR memory on a 128 bit bus). Also, the SDR memory should overclock better, plus there's more memory on the 64 MB card vs the 32 MB one. So, with that said, the SDR should be the clear choice.
As was stated above, however, if you want to do any gaming at all, avoid the 7000; it's very slow for gaming.