In my experience, most games that specify a minimum CPU speed were made with the assumption that you have a P4 in mind. Some of the newer ones have actually tried to specify this as well, when they're particularly high end, but more and more, clock speed simply doesn't matter.
So an A64, even at 2.2, should be more than sufficient.
Considering the video requirement listed for T34 is a GeForce 6600+/Radeon 9600+, I wouldn't be too worried about it.
For the record, all the Athlons are 64-bit...just because you're running a 32-bit OS doesn't make your CPU 32-bit, too.