Thank you, Drew, my fellow grammar nazi. I came in here very much to post just this.While I appreciate your use of "whom," your usage isn't correct - whom should be used in place of who when the object of a prepositional phrase. Of whom, to whom, for whom. You could ask about guitarists for whom legato was an important part of there technique, but it should be "guitarists who use legato" in this context.
That said - pretty much everyone. Satch and Holdsworth are the two guys most closely associated with the technique, but Vai and Petrucci are also excellent at it, and EVH technically does rather a lot with legato/partial legato techniques. Guthrie Govan can seemingly do anything, as well. Idunno. Think of virtually any proficient metal player, and they're probably good at legato.
BC Rich= CheckI've got you covered Boots.
Micah Scoville 8 Finger Tapping Crazy Guitar Solo Pt I - Improv - YouTube