It really depends on what you want the amp for, recording or live, what kinda of sound are you going for? Are you big on pedals or looking to get all of the sound from the amp (not neccisarily talking about effects here)?
Do you just want one so you can play loud?
If you want it for gigs, what sized venues are you playing??
It might seem over the top to ask all these questions but it's very hard to suggest a better amp when we know nothing of your style etc!
And just to clarify, youre looking to spend £200 on just the head (if thats the route you end up going... combo's may not look as 'cool' but you should NEVER ignore them!!)