The P A shop in Hanwell on the Uxbridge road does a Peavey five channel mixer amp and speakers for under three hundred quid . Its been described to me as a LOUD 100 watt which ought to do most pubs unless you are doing ballroom size rooms.Also just up the road from you is Platterpuss just by Hayes station,calls its self Karaoke but seems to have a reasonable aray of P A gear,.