Loma-Westy seems to fit the bill pretty well. For just a float trip, I've done Cisco-Moab (you can take out halfway, too, for a shorter trip) at highwater in 4 easy days. It was about 20G and there were a good number of III wavetrains, as I recall (but it's been over 10 years, so...). Dolores has some good stuff if it's running, but that's a sore subject.
Do you want a more or less "wilderness" run or would you consider something like the Ark with good whitewater and good camping but not necessarily remote?
There are sooo many more possibilities but some more info (esp. regarding time of year) would help narrow it down.
"The world would be a better place if everyone kayaked."-Brad Ludden (Valhalla)
"You only get one chance to run a drop blind."-DD