I'm not sure where you draw the line on Spanish Guitar; but Jesse Cook (well known) and Roman street (fairly young group) are good for simple, but great guitar with a Latin flair. Roman Street categorizes their music primarily as falling in the "Gypsy Jazz" genre.
The Roman Street Guitarists are brothers - lot of fun to watch in concert, especially how they seamlessly exchange lead and rhythm guitar roles!
Not writing this to be overly critical or argumentative, but I didn't hear anything that screamed 'improvisation' in any of these songs- well played and enjoyable music, but to me, it's similar to a lot of other 'Spanish Music' I have heard (and I have heard a lot of it).
Because of the lack of improv, I would hesitate to call it 'Jazz' and it's definitely not what I would call 'Gypsy Jazz', in that it doesn't remind me of Django Reinhardt, at all (whose style contains elements of Swing with strong rhythm, kept by at least one guitar player & bass and usually no drummer, even during the slow songs). However, Gypsies heavily influenced the music of many countries, so their contributions cant be denied but it's hard, at this time, to pinpoint exactly what that is. To me, it would be the fiery playing of Flamenco that comes from Gypsy music, but it's probably the slow, emotional, sonorous music, too.
Being brothers makes their interactions difficult to recreate by people who aren't related, or at least who lived together. I often imagine brothers who perform together playing as kids and trying to out-do each other, arguing about who's better, fighting, separating to play again and eventually deciding that their playing together is better than their fighting about it.
Hmmm- I just found that Milwaukee has a Gypsy Jazz group.
Django, for whom Gypsy Jazz is named-