I've got a Flextone II and some great tones, but I a) have no way of getting them to you (no computer hookup for it) and b) likely have drastically different sounding guitars than you (Squire Strat w/
DiMarzio Super Distortion,
Schecter Revenger-7) and the fact that it's a 1x12 combo mean it'll sound very different for you than for me.
I find for Vai the Rectified2, Modern Class A and Modern High Gain settings are a good starting place, even the Insane with a lot of tweaking. Haven't tried getting a Satch-like tone yet, but I'd figure it'd be either the Brit High Gain or Modern High Gain that'd get you closest.
And play around with different cabinet simulations, they really do make a difference.