I know nothing about guitars (or anything else musical) but if you're going shopping in London don't neglect Macari's who sell second hand instruments & stuff. Their window always attracts me and they seem to have all sorts of string instruments at a variety of prices.
They're:
Macari's Ltd
92, Charing Cross Rd
London
WC2H 0JA

Tel: 020 7836 2856

RtS
(no connection, not on commission!)