There a tons of cantatas for vocals, violin(s) and continuo by Handel. There are also probably hundreds of appropriate arias from Handel operas and oratorios (you don't need a full orchestra, just a violin on the first violin line). All of these are on IMSLP. You should also explore the arias within the hundreds of Bach cantatas, also on IMSLP. As you move out of the Baroque, it becomes more difficult to find pieces for your ensemble.