Here are some of the commercial people around the UK who supply Bongos.
If you contact or use any of these services, after seeing them here, please mention Bongo Buddy.

321Away Ltd, Unit 4 Lambwood Industrial Estate, Reading, 321Away LtdBerkshire (Facebook page)
Sadly, 321Away has apparently gone into administration.  (Note added December 2017).

Bongo Barn Ltd, Broomley, Northumberland (Sales) (Facebook page)
You could receive a discount if you mention seeing Bongo Barn Ltd on Bongo Buddy

Bongo Campervans & Japanese ImportsNewcastle, Tyne and Wear (facebook page)

Bongo Fury – Sales

Campers4fun, Cheshire and Devon (Sales, hire)

Campers Scotland Ltd, Grangemouth, Scotland (Camper Sales)

County Cars of Sussex, Portslade, Sussex (Bongo sales)

Discount Trucks, Newbury Berks. (Family-run business that specialises in Mazda Bongo)

Imperial Leisure Vehicles Ltd, Dorset (Bongo sales)

Mini Campers North East, Kingston park, Newcastle-upon-Tyne (Bongo sales)

Premier Bongos Ltd. Swindon – A family business specialising in Bongo & Ford Freda, hire, sales, spares and repairs.

Southern Bongos, Southampton (Sales) Has received positive comments from Bongo owners.

The Mazda Bongo Company, Cornwall (Sales)

Here are some other places to buy Bongos and related parts, bits and pieces

eBay Motors (and then search for Mazda Bongo)

Also have a look in the Parts section. In addition to parts, there are some facebook groups where members buy and sell parts, accessories, and complete roadworthy vans.