I frequently accompany our local Chorale. They are pretty good and it is a lot of fun! The director sang with Dale Warland, consequently, I have performed quite a bit of Jeffrey Van's choral + guitar compositions. He also arranged some; I'm playing his arr. of Dowland's Come Again Sweet Love in February.
Another popular piece is Walter Kittridge's Tenting on the Old Camp Ground arr. by Dale Warland.
There is a fair amount written for choir and guitar + other instruments; also there are plenty of Baroque-era pieces with basso-continuo, with or without other instruments. (Bach Cantatas! I've played the St. John Passion) If you feel up to the work, you could try your own arrangements. A few years ago, we performed Los coflades de la estleya by Juan de Araujo.