Then there's Contrapunctus 14 for trombone and guitar. Yes, THAT Contrapunctus 14.
They do a good job.
I have been working through sketches for a sonata for tenor and trombone for years and, well, shameless self-promotion here, if I were to contact an ensemble about that sonata when it's done these would be the folks I'd want to contact.
I've got some testing out of some things to do with my sonatas for guitar with trumpet and for guitar with tuba before I try tackling trombone, French horn and euphonium.