There are loads of types to choose from, R-com incubators look good but they are really expensive. £60 is the cheapest and that's only for 3 eggs :O. They go up to £280 for 20 eggs.
The more I read I think I'll make an Incubator myself. The easiest looks to make one from wood, but there are other things like, should I have a fan, how big to make it, what to heat it with etc. I don't want to spend too much money on it, as I could buy a 2nd hand one, but making one would be more fun.
I've learnt quite a few things from looking at other peoples incubators and the Omlet Forum is really good for asking questions and seeing how other people do things.