That's A LOT of gear for that set up. Bet it goes real flat in 5th or 6th.
Try something like 14/41. If you wanna keep the front 16, find like a 46-48 tooth rear.
Pipes, going from FMF to toomeys should be pretty close. The toomey's might want more main if you're referring to switching to T5's and not just the silencers. If it's just the silencers, I doubt you would need any jetting changes.