girv have a look at vipbe.co.uk its very good value, i have it in my gym and most of the main pro gyms in manchester use it
If you're buying a speed-ball/frame, I'd recommend getting a good one. You can get away with mickey mouse punch-bags and hand-wraps for a while; but if you don't have a good backboard you won't be able to hit the speed-ball fast at all (as the frame will get knocked backwards by the ball and won't provide enough force to knock the ball back towards you at speed). I learned this lesson the hard way by buying one of the cheaper speed-ball frames which really aren't any good once you start building up speed. (Also, make sure you deflate it a bit after use, otherwise it really will pop - this also happened to me.)
Lonsdale Extra Heavy bag would be a good choice from www.sugarrays.co.uk for around £130. If you have the money then the 65kg Lonsdale Colosus heavy bag for around £235.
This is the best website on the net, for buying stuff, http://www.sugarrays.co.uk/shop/ Everything you need is on here :good