SDRAM is more expensive than DDR over here.
Anyway, you should isntall XP on that system. It's definetely the best choice. You could also install 2000 if you want, but XP has better compatability and it boots faster. Less problems with XP. Disable themes and it will most likely run a bit faster than 2000.
TheMajorMMX - Intel P200 MMX @ 225Mhz - V-Tech (PcPartner) Baby-AT mb w/ Intel Triton TX chipset - Nvidia Riva TNT2 M64 w/ 16MB - 256MB M-Tec SDRAM - Still running.....