[quote name='Musky' post='1368108' date='Sep 9 2011, 09:37 PM']A bit of a 'how long is piece of string' question.
The wattage you'll need from an amp for a gig is incredibly variable, depending on a number of things like the efficiency of your cab(s), how much bottom end you like in your sound, how many guitarists in the band and what they're using, loudness of the drummer, etc.
Your budget would be a good starting point though.[/quote]
Budget is minimal, as a guide I'll say £100-120 but cheaper is better