Air Vegas
Although I didn't fly for them, I did drive the 'ditch' and have a friend at Air Vegas. I recently talked to him and seems very happy there. He is going on 3 years, with no end in sight! Flying the canyon is great experience and taught me the wonders of the C-206/207. Air Vegas flies Beech 99's exclusivley and mainly to the north rim from Henderson. The nice thing is the planes are airconditioned and turbine powered. The bad thing is you pay for the training and tour business is down since 911. The best time to get in is early season (April) and wait for the summer rush. After that it gets slow and pay starts to lean. Mins. at the time were 1000 total, 50 multi, but that has probably gone up. It's worth a shot to try, but you probably missed the 'barf' boat for this summer. Try to build some more time and shoot for next season.
Additionally, try King Airlines, Vision, and Scenic. It is a great experience and a descent way to build time, if you can find the right outfit.
Goodluck.