About filters. I had a F150 that i purchased new in 2010. I used my truck to measure mpg and how it was affected by filters, exhaust, bed covers etc. with and without each and combinations of all. K&N flat air filters. AFE cone filter. Stock exhaust and Flowmaster. Not a single drop of fuel that wasn't logged in 47k miles.
What did I find? Air filters and exhaust make less than 1 mpg difference in any configuration. So save your money on the oiled filters. If you plan the clean and re oil them, you run the risk ok too much oil that will foul the mass airflow sensor. The exhaust can make it sound good, but you may get droning that can be really annoying. The only thing that will get you more mpg is a tonneau cover. That got just short of a 2 mpg improvement.
I plan to use the Delco filter because, as has been said, parts stores are at a loss to get replacements.