I personally use autohome (they don't seem to have a web link though) they are based in Northampton. 01604 232336 but they have agreements with load of independants country wide.
You could also try
this page which seems to cover the main ones.
Have you spoken to your insurance company ? they often have deals with a breakdown co. and might give you a slightly cheaper price.
As you don't actually travel far, you will probably want a lower level of cover. If I recall, I have the 'take you on to destination' and I pay extra because I sometimes tow but I could go cheaper than that.
Personally I'd join up as just recovery from an M-way is going to be the same as a years cover and I've needed it every year so far (flat tyre and the nut holding the spare snapped off the chassis, cell of the battery died and new brake's overheating.)
The outlay is worth it for the peace of mind.