[astyanax]

Since this is your first build, I assume you won’t be over clocking, so go with the 1600MHz.
The other numbers are CAS latency and timing. Once again, not a concern.
If you are going with XP 32-bit, no need to buy more than 4 meg.
The processor you are looking at uses dual channel, so you’ll want to buy a pair of sticks, i.e. two 2meg sticks.

[Vision]

Thanks again. Will be in touch.