MostLegit -I think the best niche for a promotion right now would be a WEC style smaller weight org. There is a ton of depth in those divisions without having to spend outrageous money for fighters. His biggest asset would be Aldo.
He could take Marcelo garcia and market the hell out of him......Dana could do that now even in the ufc.
http://www.youtube.com/watch?v=i872Xv8PIWw
get Marcelo and Gsp to train together that would be sick
Chael. That is all.
Cindy
Brock lesnar. No question about it. Feed him cans of shit, build him up into a bad ass. Keep talking about how he's pound for pound. Huge, roided out, trash talkin hunter. It'd be a great start. 
MattyJ - Just say Dana falls out with the Fertitas and they buy him out but part of the deal is he can take any 1 fighter to help him launch his new company. Who does he take?
Obviously him and Jones aren't on best terms but Jones is arguably the biggest star? Chael for his fight selling but then he doesn't have the most exciting style, Anderson doesn't have to many fights left so I'm gonna go with GSP, dominant champ, marketable and a company man, thoughts?
If BLAF had a falling out with the Frank and Lorenzo he would be brought so far down to earth he'd be begging for JBJ to go with him.
Nick Diaz
without the fertittas, no one will follow the dana.
MMApostle -Malvert the Janitor - BJ. He'd fight in every weight class.
this haha
Haha
Gotta sell the fights. Chael. 
MostLegit - I think the best niche for a promotion right now would be a WEC style smaller weight org. There is a ton of depth in those divisions without having to spend outrageous money for fighters. His biggest asset would be Aldo.
Insightful
Chuck Liddell
For people saying chael what you fail to realize is without Anderson chael would be nothing. If he didn't have some big top p4p fighter to trash talk no one cares about him, wich is why after taking his beatings from silva he's moved his trash talking onto jones.
Not Chael. Not a chance. The guy has to be able to perform in the ring. There are a dozen better choices. I think the winner of JDS/ Reem is the way to go.
honestly I would take Overeem, he fights often, multiple styles, there are hwts people have heard of outside of zuffa, i think I would take him.
GSP ALL DAY
Seeing as this is all hypothetical id say probably brock. 2nd would be gsp third jbj
Rory McDonald.
Chuck.
Didnt say active fighter.. Chuck is his BFF, im sure between them and their history they would soon have an awesome org to talk about.
Junior or GSP.
Gsp seems like the easy choice. I'd say he'd take gsp, and just use the money from them buying him out to buy up a bunch of regional shows and voila, new org ready to go.