Hm... this is a good one... I would of course start out with a versatile front man... someone who can sing ballads as well as get some nice hard edge metal/rock lyrics out front... So I would have to go with Brent Smith from Shinedown... He's got that Chris Cornell ability as well as a smooth voice to sing in the lower ranges... For the guitars... I would have to put James Hettfield at rythym guitar... his chugging riffs are some of the best... Then laying down leads would be a versaitile guitarist that can play metal solos as well as throw in a good bluesy fill and play along with ballads well... that brings to mind Slash... The bassist has to be able to play along with both those guitarists and that takes me to Robert Trujillo... BUT the metallica fan in me is going to say NEY... and play my FANTASY card and say Cliff Burton. As for the drums... I'm not very educated on drummers to be completely honest but once again it would be someone versatile someone that can keep up with the guitars and add some great fills... Neal Pert is the only great drummer I can think of besides Bonham... I would probably choose a drummer from one of the modern metal bands... Like Distrurbed's drummer or Mudvaynes drummer... Either that or I would take the drummer that plays for Steve Vai. haha...
Summary
Vocals: Brent Smith (Shinedown)
Rythym Guitar: James Hetfield (Metallica)
Lead Guitar: Slash (GNR, Velvet Revolver)
Bass: Cliff Burton (Metallica)
Drums: OPEN (Metal Drummer... or Vais Drummer)