Might be out of your budget, but for that usage have you considered the i7-970/980? They are in the 550$ range, but a hexa-cores (6 cores) and support triple-channel memory. Or you could also wait for the i7-3930K (Ivy Bridge) also a 6 cores, but that will support quad-channel memory also, but possibly ~600$.
Yes, I'm getting other parts for a new rig as well, so that's out of my budget. Plus I would really prefer Sandy Bridge over Gulftown. As much as I want to get an Ivy Bridge, I think my best bet is going to be the i7-2700K right now. Then I have the option of getting a separate Ivy Bridge rig later on down the road when I have the cash, so I can run both with network rendering. For now my current goal is to have a new build within the month.
Thanks for your help.