Hi John. Over the years we have used many sound systems.
I do not recommend using a powered mixer per say.
For a good number of years we used passive mixers and power amps it is generally a better sound. Do not put all your eggs in one basket in case of malfunctions or breakdowns.
A few years ago we started using powered speakers, JBL EOn and other makes. Then I bought the Mackie system it blows away anything else. Might be a tad more expensive but worth every penny of the extra. The Mackie mixers are very good and match the active system which can be daisy chained to suit the size of venue.
My advice go Mackie.....a passive mixer, pair of 450s and a bass bin will fill most medium sized venues (200-400people) with the best quality sound you could hear. Money from a couple of gigs should pay for it.