Jarrett is going to be the odds on favourite to be the leader. I can easily see it being his new faction. It could also see a return of Matt Morgan, he has disappeared (rumours he isn't on the roster but he's still on the Impact Wrestling Roster on the website) since teaming with Crimson. Could also be King Mo's entrance into TNA? Magnus? Gunner? Crimson? I think this is going to be one of the best storylines in a long, long while in both TNA and WWE.
Karen Jarrett did say expect something big from them soon a short while ago on twitter. It would be an okay angle, Jarrett, the founder of the company, being pushed out, and now he is coming back to claim what is his from the people who took it from him. (Altho JJ was in Immortal with Hogan, it's clear they would not be cool now)
I'm fond of Matt Morgan, he's decent in all categories for me, but he doesn't have that presence, or "IT" charisma that a big guy needs to really get over (Nash). I would prefer they let him go back to WWE and let them have another try at him.
And you will call me a hypocrite for my last statement, but I think they should bring Chris Masters in as one of the guys. Like what he has done in recent years to improve his game.
Gunner could be one of the gang guys, but should not be the leader henchmen, if they are going to make it that way.
Magnus is in the BFG series, he just did a promo saying he is gonna win the tourney on Thursday. Same goes for Crimson. He has no reason to be involved in this. It's not gonna be anyone that's been on TV in the last month.
For people saying Batista/Goldberg. Batista is planning his first MMA fight soon, he deeply committed to that career path now, and other things, he would have no interest in TNA, WWE, or maybe any facet of wrestling at this point. Goldberg has always been a shit worker, if you aren't having squash matches (that are just gonna kill our established stars/upcomers) the fans are gonna see through him afterawhile, and turn sour like some have on Hogan, Sting, Angle, etc. Not to mention he is old, and haven't been in wrestling for years, which means he is gonna be even more shit in the ring than before. He won't hold the same frame/muscle he had a decade ago, and won't look as impressive (same with Batista, especially now that he is in MMA).
Ring Ka King is a good idea, or AAA, but the guys they have in those orgs, can't fit the bill for "Biker Street Gang".
So the most plausible, and seemingly best routes for this storyline are:
A) Jarrett comes with a bunch of henchmen, which are young guys, who deserve a shot, more of what Gut Check and X-Division tourneys have done, which I love. (Get away from the old)
B) It's a group of thugs, where the leader is gonna be most important, and they will try to break him here, and the rest of the gang are just ham-n-eggers. If the guy is semi known, they could have them all unmask one by one, with the last one being the leader.