The F-15 was mentioned on the 'Future Carrier' thread, presumably as a vote for the 'cover the fleet from the land' theory; which would of course mean yet another new type for the Navy if we were keeping the FAA.
Personally I think the 'easy-fit' cat n' trap facility on the new carriers is solely to make them easier to sell, and the only time the Royal Navy will get to see them is when they go past on delivery...
If we should get to keep them, it's hard to imagine getting F-35 as well, hence my suggestion of Harrier 2+.
I am aware of AMRAAM launch velocity and acoustic vibration issues, but unless we spend really serious money, can't see a better option.