iMac or MacPro?

I am looking to replace several older Mac's with new ones. The MacPro offers quite a bit of horse power but the price is not very appealing (I am not opposed to buying them though). The Mac Mini while nicely priced doesn't seem to offer the higher performance that will likely be needed for a prepress environment. For price and performance, iMac seems like the way to go.

Your opinions?

Thanks,
pd