Since my initial post was really really long, I've condensed it into this spoiler box:
If you'd rather not read all the details, here's the TL;DR version:
-Add another kind of hardpoint to aircraft, Support Hardpoint, located on the underbelly of the aircraft.
-Add Support Packages which can be equipped to Support Hardpoints and Heavy Hardpoints.
--Enhanced Sensors Package (ESP): increases radar range and detection rate of aircraft, used for scouting UFOs and Alien Bases
--External Fuel Tank (EFT): Adds extra fuel to the airplane, allowing for increased operation time, range, etc.
-Penalty for using Support Packages on Heavy Hardpoints is you have less missiles or torpedoes to use in air combat.
-Penalty for using Support Packages on underbelly Support Hardpoint is: slower aircraft speed in geoscape and dogfights, no using evasive roll or afterburners in dogfight.
-Ability to eject underbelly package in dogfight to remove penalties in emergencies.
-Small cost (in purchase initially, then in manufacturing) for External Fuel Tanks.
-High cost in manufacturing for Enhanced Sensors Package.
Anyway, comments?