Great suggestion Tostado. BS had three guitarists, Richie Furay on rhythm and both Stephen Stills and Neil Young on lead. Neil is not to every guitarists liking, but he sure has his own style!
Another band with three guitarists was Moby Grape, whose first album is absolutely essential listening.
Max, a group you have to hear if you haven't already is The Byrds, who highly influenced many current artists, both guitarists and songwriters. Tom Petty, REM, many, many others. Not just Jim McGuinn's 12-string guitar sound, but the guitarist in a later version of the group, the legendary Clarence White, master Telecaster player. Gram Parsons, who joined The Byrds after David Crosby left, is a songwriter of guitar-type music who cast a very long shadow, influencing a great many who followed him. Gram also made two very influential solo albums, introducing the divine Emmylou Harris to the world. Before he died, he had a huge impact on Keith Richards, introducing him to real country music. Keith wrote a lot of music with a country influence after that.