These are my six¹ favorite² guitarists, listed in reverse order of when I first came upon and learned to love their music. Please recommend others.
Ben Monder³
Eivind Aarset³
Ava Mendoza⁴
Michael Brook³
Bill Frisell⁵
Robert Fripp
¹I likely forgot some.
²Ambientish and living
³Never seen live
⁴Used to see often in San Francisco before she left town
⁵Used to see often in New York City before I left town
A few that come to mind right off the top (not all exactly ambientish but all living, I think):
Dr Know (Bad Brains) Mary Halvorson Sumner McKane Oren Ambarchi Richard Pinhas Sharif Sehnaoui Robert Hampson
A few of my favs: Johnny Guitar Watson Leo Nocentelli Jimmy Nolen Andy Summers George Harrison John Lennon Kenny Burrell Jan Akkerman Bas Krumperman Eddy van Halen
I recommend Manuel Mota from Portugal, manuelmota.bandcamp.com