If you're sticking to just metal and neo classical metal then you're only going to find variations on the same old stunts.

If you want to explore jazz, classical, and avant rock players with unusal techniques then check out people like

Dan Stearns
Ken Rubenstein
Shawn Lane
Henry Kaiser
Vernon Reid

etc.

you can find links for all of them on my page:

http://kronosonic.com

Many of them are doing microtonal and fretless but none of them are doing metal -- so it wouldn't be for everybody I suppose.