Recommendations for some nice intermediate-level pieces for a wind group (i.e. clarinet, oboe/flute, bassoon) or a mixed wind-strings group?

I hardly recomend you to visit the site: http://dichmusik.dk/ where you can find nice arrangements for any kind of instruments  combinations.

I'm a cellist and usually play trio with a flutist and clarinetist. It is not so easy to find music to play for our trio. This website  has helped us a lot.

Hope to be helpful !

Bet Prats