Here are the memory specs, if you need them for your mobo.
Number of DDR Slots 4x 184pin DDR
DDR Standard DDR 400 (PC 3200)
Maximum Memory Supported 4GB
Dual Channel Supported Yes
This Corsair ram looks pretty good and is on the cheap side.
333mhz ram should fit on your ir mobo as long its 184 pin. I'd advise staying away from slower ram since it would only make your other ram sticks downclock, and would lead to a performance loss.