Might be out of your specified location, but the Owyhee in southern Oregon is running right now, and would be a pretty comparable self-support.
American Whitewater - 1. Three Forks to Rome, Owyhee Oregon, US
The drawback, of course, is that it'll be a cold expedition: Rome, Oregon (97910) Conditions & Forecast : Weather Underground
But the word is that it's a pretty spectacular canyon with quality whitewater (plus no permit), so with a drysuit and a good sleeping bag, it might fit the needs of an early season trip. It's always been on my list; I just haven't made it out there yet.
I'd prefer the Salt too (60 degrees vs 45), the other math doesn't favor AZ (144cfs vs 1,250 in the Owyhee).
Hope it works out - if so, have a great trip....