I don't as yet know any firms in the area (good or bad).

I'm looking for a ball-park figure first and I don't want to have to get people out on site (as they will probably tell me they have to before they can quote me). Also I might need to know quicker than they could reply to me.

As another thought, there may be different ways of doing things, concrete, tarmac, blockwork, etc. not covered by the same firms.