Hi mate - If you're looking in halfords I'd recommend having a look at the Boardman range too as they seem to be fairly high spec'd for the money compared to other brands.

I've got a specialized stumpjumper ht as my main off roader, but also recently got a boardman as part of the cycle to work scheme: http://www.cyclescheme.co.uk/ so check with your employer as this can give you a big saving on more expensive bikes

Ben