What'cha gonna do with the Imac? Make an aquarium?
For business apps I honestly don't think you'd need anything over the 2.4, but ask Beebster first -- maybe the hyperthreading would be a good thing for you.
Can you order a 5660 without any ram at all and put in two sticks of 512 from Crucial? Would a person be saving that much by doing it?
If I'm looking at this correctly, it's $410 for 2 sticks from Torque, while it's only $280 from...