I'm in the midst of a long overdue shop redesign and considering upgrading my 2hp HF DC. Id like to build in some PVC ductwork this time. I've got about 20' to the front of the shop (garage door) and 13' of used space across the back wall. Right now my plans are to run the largest machines along the back wall. It would be nice to place the D.C. at the front of the garage- for noise and fresh air (side door w cross winds)

I think a 20' run and a 13' run would be more than the HF can handle. I have a 8" jointer, cabinet saw, a 18" BS, and a box planer. Plus some smaller tools like a miter saw.

My budget is pretty light which is why I'm posting this question. I just picked up the (used) cabinet saw and also upgraded my planer. Could I make much of a gain with $600-700 to spend or would it be worth waiting to buy a cyclone designed unit w a 2-3hp motor from... for $1300 or so?

If I buy used I'd like a large enough impeller and hp to buy a XL Dust deput. I could also build a separator but I don't want to lose too much CFM with a poor design. There are a few used 3hp double bag DCs available near me. The one in town is an old Grizzly for $500. About 90 minutes south is a Powermatic for $600. (I'm in Louisville). The double bags are going to take up more floor space but the improved CFM is attractive.