Hello & welcome to the "FUN HOUSE"
You really do have a rare breed of Charger on your hands, although I would expect to see more and more of them as dealers begin to put more "fleet" vehicles out on the street, and rental car companies rotate stock.
To my knowledge, you may just be the 1st 2.7L owner here, although I think we may have an owner from Canada that has popped in here before. Up there, the 2.7's are more common.
Anyway, the first three (and most available) performance mods out there for the 3.5L engines and the CAI, catback exhaust, and Jet computer module chip. If you do a search, you will find many dozens of threads on these topics. I can say that I have done all three to my SXT, and am very happy with the results for the $$$'s invested.
I can say with the 2.7L engine, that K&N Products does have a CAI for the that engine. It is product #63-1544. IT IS NOT that same part as the one for the 3.5L engine, but looks very similar.
The Jet chip module for the 2.7 is the same as the one for the 3.5 (no difference).
With the exhaust, there are several makes out there (Mopar, Magnaflow, Zoomers, etc.), all have varying levels of price and sound (growl) levels. I haven't seen anything advertised specifically for the 2.7L engine, so you will want to make that you check with those vendors to make SURE that there aren't any connection modifications that need to be done in order to make it fit. If there are differences, you will need to determine if a muffler shop can do some kind of custom adaptor(s) to make it work.
Hope this helps & WELCOME aboard!!