I would love enough money to get a proper system like the pickups and amps and Fishman pedals described in this thread, but for a quick and dirty solution to the problem the Behringer can't be beaten. The P.A. We rehearse with is OK but not fantastic and when the rest of the band come in after the exposed acoustic bits then the sound is pretty decent in my opinion.
So thank you for that recommendation. I will refer to this thread again when I get hold of some more cash because having heard what a twenty pound box of tricks can do I would love to be able to afford something better...
Thank you for the practical and fast advice - it was really helpful.