I don't recommend the K&N Drop-In filters, they don't fit in the stock airboxes very well, which could allow unfilter air to bypass them.

If you want aftermarket performance air filters, go with an complete air intake.

These sold from Needswings seems to be popular on this forum: https://www.needswings.com/intake-xf

As for exhaust, I didn't go with a catback exhaust, but instead just changing out the muffler for a better sound. I'm going with Flowmaster Super 44 (2.25" in with dual 2.25" out) and having my muffler shop weld it in place. About $250 including the price of the muffler. You won't see much in the way of performance gains, mostly sound.

Here is the catback Magnaflow system sold on Needswings as well: https://www.needswings.com/magnaflow...exhaust-system