What guitar should I buy?

okay... I have a not very good guitar that I got in a starter pack. I have been playing for about 2 years now and I'm saving up £300 for Christmas, my mum said that if I save up and I don't have enough money to buy the guitar I want she said she would pay the rest... So now I have to decide what guitar I want. I like Metallica so I want to get a good electric guitar a bit like James Hetfields. My budget is probably going to be around £400 so does anyone have any ideas for a guitar to play in the style of Metallica, Iron Maiden etc. thanks for any ideas.