What would you do?

Only you know the answer...... People can praise OOTB TTI or whomever for these cars but the fact is they just don't fit like a daily stamped out header from the factory for a Chevelle. You can get thrown out of a track for no cage with any of these scenarios so the choice is yours. Mild to wild. IMO if you want to enjoy your car mostly for street driving then set it and forget it with B. Your C option ups the power ante but that can require maintenance as where Manifolds are pretty much a plug and play....

Enjoy,
JW