Purr if you start a TNMT game, would you consider letting some characters in from Heroes Unlimited or Ninjas and Super Spies? I’m not in possession of those books until they ship out later on this year.
The other option is to buy some of the PDFs. If I did that, what books would I need?

One reason I feel we are not playing Sharseya is because I goofed and made it too complicated with my desire to transfer Pathfinder to Palladium. I run the risk of repeating my mistake if I choose to allow characters to one universe from two more. Heroes Unlimited incredibly- complicates things.
I also feel that by adding it, we're not really playing the game I want to run!
This is one of the reasons I'm shying away from playing Rifts right now - not only can it quickly become complicated, Rifts characters tend chase power. I would rather instead not to focus so much on power and instead go after more... goodness.
Bookwise, Bud, I think After The Bomb is the way to go because base-TMNT is just plain broken. This is one huge reason Palladium's Sean Roberson is turning the TMNT books into a "revised revision." Roberson stated frequently enough during the kickstarter that he was not changing the game but editing it to provide greater clarity while fixing a lot of the mistakes in the books.
If folks are serious about wanting to play a TMNT game, then I'll have to look into the books first to be sure if After the Bomb is best. If not, we'll have to go with the old TMNT RPG which I guess I'll provide.
But I won't go that far until everyone decides that that's the game we want to play.
One more important thing. Expect house rules. I want there to be a mystical aspect to a TMNT game I run.
Do you remember Big Trouble in Little China?
Well, you may as well call my game "Big Trouble in Teenage Mutant Ninja Turtles" because that's how I imagine I would run it! =)
I would add details here but this is a long enough post. =)