Spitfire LF.Mk XVIe (a Spitfire LF.Mk IX with an American built Merlin instead of a British built Merlin):
Sea level speed: 336mph (Spitfire F.Mk IX does 321mph)
~20,000ft speed: 405mph (Spitfire F.Mk IX does 408mph at 26,000ft)
Initial climb: ~4,400fpm (Spitfire F.Mk IX does about 3,900fpm)
Better roll rate and turns slightly worse than non-clipped Spitfires.
Bf109G-14 (a Bf109G-6 with MW-50):
Sea level speed: ~350mph (semi-educated guess)
~22,000ft speed: ~415mph
Higher initial climb than the Bf109G-6, but I don't know how much.
Handling should be very similar to the Bf109G-6, but with better visibility out of the cockpit.