Second the Dynacord suggestion from Pat Cooksey.

I have used a slightly smaller version (200 or 300W per side) but for design, portability and sound it was excellent.

You might check out the Laney PA systems. I think there are 8 and 10 channel power-mixers with matched cabinets at a decent price and the quality is fairly reasonable.

Now that my "band" days are behind me I tend to use a combination of acoustic combos (Trace Elliott and Laney) and a Behringer bass combo, mixed or singly according to to the needs of the venue.

Peace

moo