Declan, I think you are going to struggle a little with your budget, I race on at seaham also, it seems what you have at the moment is ok ish to get you going, I'm not sure if you can extend your budget or wait a while, save up and spend a little more on you electrics as if you are buying cheap you may end up buying twice as you get better or want more from your setup
Here are a couple of good motors on offer
http://www.jemodels.com/megaspecials...tegory_id=1423
http://www.jemodels.com/megaspecials...tegory_id=1423
As for a ESC, if you was to buy new I would say you need to be spending £100-£150 ish I would say as I'm guessing you want to upgrade on what you have now?