Zim has it correct. DDR2 and DDR are *NOT* compatible. You cannot put DDR into a DDR2 motherboard, and you cannot put DDR2 into a DDR motherboard. For one thing, the pin counts are completely different: DDR has 184, DDR2 has 240.
If you're going to be using the socketA Epox, you should just pick up some PC2100 off FS/FT, ebay, etc.
Edit: Given that PC2100 isn't much in demand anymore, it might be cheaper to buy PC2700 or PC3200. This is fine--the faster RAM will just run at slwoer speeds (I don't believe this Epox can run the FSB & RAM at different frequencies).