Larkin,

what sort of gear did your banjo player use - perhaps that will give some guide on power.

Do you need the whole lot - mics, stands, cables, mixer, power amp (or powered mixer), speakers, foldback etc? or just a PA mixer amp and a couple of speakers.

Everybody has their own preferences on brands but for pub gigs it's nice to keep it simple. I use Beyer and AKG mics, a powered mixer (Studiomaster but there are other equally good makes) which can provide power for front of house and foldbacks when required (350W per side) and either EV or DAS speakers (again take your pick from other brands such as JBL).

I believe you're in London - take a look at Studiospares www.studiospares.co.uk who have just moved from Camden Town to Staples Corner.
They have the Fender Passport portable PA as well as powered mixers by Yamaha, Stageline and Soundcraft and speakers by Yamaha, JBL, and Samson.

Mitch