I understand that the money is a concern but consider the amount of time that you want this machine to be viable. The mac pro can be expanded with more HDs and a TON more ram. The imac is a great machine for right now, but will it be a great machine for your needs in 2-3 years? It might, it might not.
If it were me, I would go for the mac pro and plan on keeping the machine for the next four years or more. Just wait for snow leopard and cs4 and you will see major bumps in speed hopefully.
If it were me, I would go for the mac pro and plan on keeping the machine for the next four years or more. Just wait for snow leopard and cs4 and you will see major bumps in speed hopefully.