please for the love of god dont get an onza t-rex, try out some different bikes mod an stock to see what you like most, and consider 2nd hand (if from someone you trust/with a good history of the bike) for £600 you should be able to pic up something decent 2nd hand, or for more new, i reccomend going for any of the deng frames (they're very popular an have a good reputation) gu, zoo!, echo, adamant, all good bikes. or for that money you could build your own spec from scratch (much more fun ) anyways get yourself a bike an go ride