There's are some details here that need clearing up.
Actually, the G4 iMac and G4 towers have the same processors. The difference lies only in the amount of cache and bus speed. However, the 800 MHz tower lacks the L3 cache that makes its big brothers perform *much* better. Thus, the only advantage the 800 tower has over the 800 iMac is the faster bus. If you are doing calculation-intense work, which I assume you are, you will indeed notice slightly better performance with the tower, but nothing extreme.
The tower will let you connect any kind of monitor to it. This is a big advantage over the iMac; it can have multiple monitors to spread out your workspace whereas the iMac only allows you to connect a single monitor to "mirror" the built-in display (which has a maximum size of 1024x768).
The G4 "workstation" will likely be your best choice. It offers not only better speed but also far greater expandability.
[ 04-23-2002: Message edited by: starfleetX ]</p>