Since no one answered. I know Southwest rented out a bunch of spaces in lot C starting a year or so ago, but I don't know if that is only for on site employees or if people commuting can use them.

Superpark is on airport property lots, they do monthly fees in the terminal lots, I assume you can do one for the futher out lots but I don't know. Parking spot also has a handful that I would guess you can do a monthly fee. Those are the main two but there are others around.