I think Yes already are that prog supergroup. They already have Jon Anderson on vocals, Steve Howe is in (my) top five gutarists list and way better than Fripp. Is Keith Emerson really a better keyboard player than Rick Wakeman? As for the late great Chris Squire on bass, well lets just say Geddy Lee was inspired by him. As for drummer, I would opt for Geddy lee's bandmate also no longer with us Neil Pert.