Another option is an overhead track and trolley. Even though the vise and 4th axis are a b***h to lift, they're lightweight as far as material handling hardware is concerned, so it needn't be expensive.
For about $50 at McMaster-Carr, I got a piece of Unistrut track and a four-wheel trolley. I lagged the Unistrut into the joists over the PCNC and was good to go.
The only other thing needed is a chain fall, which you may already have. If you don't, Frank Ford shows how to make a nifty one on his website:
http://www.frets.com/HomeShopTech/Pr...minihoist.html