* F-16XL Delta Wing variant.
* Diverterless Supersonic Inlet
* And the one that hasn't been done add the F-119 engine and Vectored Thrust off a F-22.
The last one I think is do-able. With the XL being longer and the F-119 a longer engine, I say why not. Especially since it would take you up too 35,000 lbs of thrust and give you supercruise potentially.
I read the XL was a heavy hauler and gave a F-15 variant a run for it's money in a fly off and lost because of politics. Yes at best this junk yard dog might be Gen 3+, but with the maneuverability, heavy hauling and range how could this not be a versatile addition to the fleet. While it doesn't have robust landing gear and a huge gun, how would it not be a compliment to the A10?
This picture below is close to what it would be, add the F-22 Turkey Feathers to it and you get the picture.
I like the “American Grippen” I just read about.
Delta wings inhibit roll-rate sacrificing maneuverability in a fight. OTOH, the provide extra volume for fuel (range) and area for extra hard points (more weaponry). In order to give a Delta maneuverability you might need canard in addition to your vector-thrust. Just buy a Rafael or a Typhoon.