I understand why you would want to buy local, theres the customer serivce, the fact you can view the products before buying, the ease at which they are on hand to help with any queries, buying over the net can in many case prove to be more expensive with hidden delivery charges, or you are not at home when its delivered so you have to spend petrol collecting sometimes from maioles away from home i fthe company the use happen to have no depot near you and little to no customer serivec if anything goes wrong.
Milton Keynes has many places to try but a good place to ask for advice on the local area is here http://www.mkcruise.co.uk/ click on the forum.