Mild to Wild also runs a good operation there. The Salt, however, is very hit or miss for flows, especially since it sounds like you have a relatively early spring break. This year has been awesome but some years it doesn't run at all. It would really suck to buy plane tickets and get skunked. There are plenty more options that might fit your bill, too though. Cataract Canyon in Utah is awesome, guaranteed to be running, and has good side hikes as well as some classic climbing, biking and canyoneering around Arches National Park near the put-in in Moab. Definitely look into some alternative plans.
"The world would be a better place if everyone kayaked."-Brad Ludden (Valhalla)
"You only get one chance to run a drop blind."-DD