I've been looking for a new PA system for parties as well as putting on small acoustic gigs, mainly to amplify vocals, and maybe the odd bass guitar or keyboard.

Gear4Music sell a bargain PA system which is only £125 Inc VAT. This features a separate 100W  RMSamplifier with a built in four channel mixer including 2 band EQ on each channel and 3 band master EQ. The speakres are 100W RMS 10" units in carpet covered cabinets with pole mounts should you wish to mount them on stands. The package also incldes two 6m speaker cables, so everything you need to get going.

Gear4Music also sell a large variety of studio and live gear as well as instruments and computer audio equipment.