Hi Bob,
The official response is as follows...
"The Rainbow Bridge flight is at 07.30 and the Bryce Canyon at 08.30 and depart from the same airport. The only problem would be if the 07.30 was delayed. If he had to chose then I would probably go for the Bryce option. Please advise him that these 2 flights and the Monument valley flight are subject to numbers whilst the Papillon flight isn't."
With all that in mind, it is recommended that you book before leaving the UK so there is a better idea as to whether these will operate.
Hope that all helps,
Julia