Farrell,
The iMac 24" will do everything you need, performance-wise.*The only question is whether the screen size will be big enough. You could run a 30" screen off the iMac if 24" didn't prove enough – it has a mini-DVI port on the back. Despite having either a 256Mb or 512Mb graphics card, it won't be able to support the full resolution of the 30" screen (2560x1600) as mini-DVI only supports up to 1920x1200 dpi.
So, if you want a 30" screen at maximum resolution, the only way is to get a Mac Pro (or run it off a MacBook Pro
).
Have you investigated Spaces in Leopard regarding your window layouts? It might be an answer to using up screen real estate.
AppleMacster