You might want to look at RIB Scopema in France. They make just about every seat configuration possible. You did not say whether you wanted a seat that also serves as a bed, which is one of their specialties. They are widely used in european conversions - the single width seats are designed to use the front seats as part of the bed. Obtaining mine was truly a saga, but possibly you can work thru Kiravans in England if you want one as they seem to keep stock on hand. The Kiravans site also has a lot of useful information including how to do a proper installation.