Team Leader:
Jolt
Always the little sister of the group, I'd like to see her get some proper attention leading her own iteration of the Thinderbolts, especially since she has been on Counter-Earth for some time and likely has gained experience. She wiped the floor with the Masters of Evil immediately upon returning in Zub's run, but sadly havent seen her since.
Kindred
Thunderbolts have always been involved in some level of taking over a namesake of another character, I would love to see Infestation from the Hellfire Academy in the guise of Kindred, with a small retcon of her powers being demonic in nature and drawn from the same place Kindred's do.
Scream
Andi has always been a bit directionless since Flash's death, I think her being on the Tbolts is the exact empowerment she needs to find her own footing.
Detroit Steel
A mecha because why not? Doug Johnson was decapitated by Sasha Hammer back in IIM, but let's say his brain got shipped off to a place like Shadow Base and ended up piloting one of those robocop 2 brain-mechas we saw in Immortal Hulk. He'd also very much fill the self centered character of the lineup that has their own agenda.
Star
I've really liked her so far in the KiB miniseries, and out of everyone shes the only one who comes close to what the Thunderbolts are. Would love to see her explored more in another lineup like this.
I'd also love a villainous corporate Thunderbolts as a foil to this group. Would be led by Moonstone, who is actually Justine Hammer impersonating Karla. A B-Plot involving Iron Monger, Sasha Hammer, and the Power Elite who have been on the hunt for Justine, Detroit Steel is wrapped into this, etc etc.