All tours are the same. Just go there and sign up at the site.
Upper is a zoo, all the time. The only advantage of the "photographers" tour is that the guide will stop foot traffic for a short time to give you a chance to shoot an empty scene. But then you will be jousting with several others trying to set up their tripods. Guys trying to do bracketed HDR shots at low ISO can have up to a 1 minute set, which they then try to repeat a few times.
A cheating tip posted long ago... Start with your official tour, but then get lost. Just drift away. The guides are not paying much attention. Then browse as long as you want. Go forward, go back, wait for a good shot. When finished, go out and beg ignorance to other guides. Hitch a ride back on any available truck. Probably get to ride up front with the driver.
The lower canyon is a little less scenic and is thus less popular and less crowded. A far less hectic experience, but still a lot of good scenes. Last time I went in the Upper I was on a truck with 18 people and 7 other trucks were parked at the entrance. Last time I was in the Lower I was in a group of 8 had no problem with the groups ahead or behind. No trucks at the Lower, you just walk in. The truck ride to the Upper is an experience of itself, depending on how drunk the driver is. Not for the weak or feeble who can't hold on for dear life.
Take a plastic bag to cover the camera. The guides like to throw sand on some of the structures to let it drift down. The sand is very fine and goes everywhere.
