Electric guitarists: Does anyone know how to improve tone in the higher fret region?

OK – I’ve been fed up with this for a few years now! When I play notes on the top two strings (E and B) the sustain is short, the notes sound is ‘tinny’ and it’s uninspiring. What do I need to get a nice rich tone with more sustain? I listen to some pro guitarists and their guitar sounds great wherever they play on the fretboard. I know there are several things that affect tone: strings, fingers, FX, guitar woods, pickups, amp etc. but can anyone help? I’m going for a sound like Dave Gilmour, John Mayer, Clapton, SRV etc.

A few thoughts :
1. Maybe your strings are too light gauge, I think heavier strings may ring longer.
2. Maybe your action is too low, so you get some fret buzz.
3. A Boss compression-sustain pedal may help improve your sustain.

LDS Hymn Adam-ondi-Ahman 12-string acoustic guitar Mormon