I have found that a number of the polkas that I have written for brass quintet/woodwind quintet lend themselves very nicely to string orchestra. With that in mind I am in the process of repurposing several of them and hope to have them up on the website soon. Periodically I will add a few more to the site under the Music for Strings heading.
If you are looking to make a short statement using minimal forces, then one of the 50 Dispatches I have written might be the ticket. Written for anything from two instruments to five instruments (a couple of the quintets supplemented with percussion) these short statements run from around 01:00 to 02:10 and range from easy to medium easy to medium degrees of difficulty. Almost all of them can be seen/heard on the J. W. Pepper website
I have created quite a number of easy to medium polkas for brass quintet with versions also for woodwind quintet (different keys). The blueprint is pretty much the same with the melodic content changing in each title and each comes in around the 3:00 minute mark. They can be used for a variety of occasions and are great for teaching small ensemble cooperation. I have titled each one using a play on the word Czech as in Czech Mate! Polka, Rain Czech Polka, Czech Please! Polka and so on and so on