Avoid the MG series like the plague.
The AVT series are probably alright for practicing with but aren't really worthy of serious gigging consideration. If i were you I would avoid spending £200 on a head and save up a bit more money to get something much better. Whichever way you look at it £200 won't buy you anything you won't regret later on.
If you save up around £400 you could get a second hand DSL 100 or 50 which would be much much better.
Bear in mind that you need a good cab for your head to sound decent...