Good move re the GC trip. You will definitely be able to book while you're there. There are guys on the strip near Planet Hollywood and the Monte Carlo handing out flyers, but usually for companies I've never heard of.
I have read that you can get a good deal if you go on standby, ie turn up early morning and see if they have a slot. Wouldn't want to risk it personally.
We did the GC when we first went to Vegas 19 years ago. Got a bus to Boulder City and a flight over the canyon. Hated every minute of it due to the turbulence which was horrendous. We have considered going back, but only if it was a chopper direct from LV.
Then there's the debate about whether you are seeing the "real" canyon if you go to the West Rim. I must admit that it wasn't the lovely red colours I was expecting and was just sort of brown.
I put that down to the time of day we were there which must have been around midday to early afternoon. However I've read that the West Rim isn't as colourful.
I am really looking forward to your experience so that we may consider it in November.
We saw Mystere and, although the acrobats were really good, we decided that perhaps Cirque just isn't our thing. We are considering seeing Love and Elton John again in November. The only show that's a definite is Legends in Concert as I have a 2 for 1 coupon and it's a good show.
luci