Foundation of an unplugged cover or songwriting combo

Hello,
I'm Martin (45) from Kiel and I would like to found an unplugged combo and I'm looking for anything but cajon and rhythm, because I play that myself.

Like this:

https://www.thomann.de/de/meinl_cajon_drumset_conversion_kit.htm

So we are looking for: guitar, piano (keyboard), violin, vocals etc. etc.
From my experience, the song or material depends a lot on the people and personalities. If the chemistry is right, there will be something to rehearse that is fun for everyone.