^ ^ +1 on TO.
What about a laney gh50L with framus 2x12?
that should come to about £600. Haven't tried the framus 2x12 or the laney (er, maybe you should disregard this advice completely, lol, this isn't boding well), but the other laney tube amps I have tried have been great for the cash, and v30's are pretty decent speakers.
Alternatively, the peavey windsor is pretty nice, though it's very 80's toned. And the cleans aren't amazing. No reverb either (mightn't be reverb on the gh50 either).
I'm guessing that either of those will sound better than the LV (i haven't tried the LV).
But echoing what TO said, at least if you have a good head, you can work from there and upgrade the cab (or buy a reverb pedal) later. You'll probably lose less money that way too.
^ tell me where you can get a cornford head and cab for £600! If you can, I'm there! :D
EDIT: another thing is, a lot of people would say you could get a better amp if you go combo than halfstack, at your budget (unless you can nab a really cheap but decent cab somewhere). Something like a laney tt50 combo would be almost within budget (I think I've seen them for about £670).
Of course, it depends how badly you want a stack.