Wishing for the Beatles is to me wishing for them as they were and that wasn't even a constant so sure, not realistic but hey, it's my dream.
To the rock/blues thing . . . that is just too much for me narrow down.
My favorite female vocalists were Linda Ronstadt and Ann Wilson. Stevie Ray Vaughn and Billy Gibbons are up there for me as rock/blues guitarists. Don Henley is just fine for drums. And would still take McCartney on bass with any group. Would take way too much time for me to single out just one keyboard player and although Elton John and Billy Joel would be way up there for me, but I could come up with a whole bunch more maybe not so singularly associated with keyboards, but in some great bands over the years.
Ask me in an hour or tomorrow and I'll probably have some other folks, or even different ones, lol. So many different "super" ensembles that could be put together and just scratching the surface.