I don't know if they are available in the UK but the Thunder Tiger ST-1 has quite a following. It is available in the US for $299 at the moment from amain:
http://www.amainhobbies.com/product_...ducts_id/17281
It is built well and has a strong engine for an RTR. The servos will last for a little while but regardless of the brand you choose, the servos in the RTR will not be that great.