Simply put, choose the best (in your opinion) in his or her field, and make your own bespoke supergroup.
Here's mine -
VOCALS - Claudio Sanchez (Coheed and Cambria)
LEAD GUITAR - Tom Morello (Rage Against the Machine/Audioslave)
RHYTHM GUITAR - Dave Murray (Iron Maiden)
BASS - Les Claypool (Primus)
DRUMS - Joey Jordinson (Slipknot)
EDIT: BACKING VOCALS - Maynard James Keenan (Tool)
Over to you