Spike the simple answer is not really i did find one at £3k + courtesy of ?? i will come back to you on that one, what i can tell you is the people who made the roof i am currently having installed are intending to make one if they have not already done so, and how much i am unsure of, but i will check and come back to you, mine is a Remio copy lay low pop top ....having been going to do a similar conversion a short while ago, myself.... What a lot of people tend to do is to fit a Swb one front wards and use the rear with a custom made roofrack which if done well looks good and is practical, it is the same with high tops very few making for lwb as against swb as there are so many more thousand swb's against lwb on the road...
Well mine is being fitted with one as we speak 