I'd keep the A2000 assuming it is an ECS model. The A3000 might have the built in SDFF and Z3 slots, but the A2000 has more space inside for expansions. Also, as you have a CPU card I assume you have SCSI on that which is probably better than then SCSI on the A3000.
My A3000 sits on a shelf while my A2000 and A4000 get played with.
