Telephone an independent kitchen fitter / company they will normally do this kind of thing for you, mind you it's not cheap. expect to pay about £40 to £50 a joint
This is not such a rip off as it sounds, the router bit costs about £45 and you only get 4 or 5 cuts from it, then the cost of the bolts, jig, travel, labour etc.
You will find the big sheds are usually not interested. ( not enough commission for the salesman , I suspect )
Not many joiners get enough worktops to justify the cost of the jig and tools, unless they are fitting kitchens regularly.
Hope this helps
David