If you are willing to haul around another keyboard as well as the behemoth G70, I'd say go for the XK-1. If not, either the XM2 and drawbar module (or forget the drawbar section if you don't mess with them live, just use presets), or the Nord Electro Rack and drive it from a G70 Part. This would gain you some killer Rhodes, Wurli and Clavinet sims,, too (as well as a Farfisa/Vox for those sixties oldies!).

The only thing I wouldn't really counsel is the laptop B4 thing, unless you are VERY comfortable with a laptop onstage, and don't mind the fiddly little wires coming in and out of it, external MIDI interfaces and soundcards to hook up and break down, and the basic fragility of the whole thing. It can and does work great for many people, but you should be aware of he issues...

Finally... Why not pull the Muse from the big rack, and get it a little rack all it's own? That strikes me as the cheapest, most reliable solution...