OK, so if Sir Muir and his team are no good, who should be on the panel? - people who are suitably qualified in the areas the inquiry are going to examine, but without the environmentalist baggage. Here's a few thoughts:
IT areas: John Graham-Cumming has suggested himself as a candidate and he would certainly be acceptable to both sides.
Paleoclimate: someone at CA suggested Atte Korhola. Perhaps not acceptable to the other side though.
Statistics: Ian Jolliffe?
Peer review: Harvey Markovitch? Ex-BMJ - expertise in research integrity and peer review ethics