I have no affiliation with either of them, but researching similar trains of thought when we bought our Weekender, I came across these two companies which seem to be doing interesting things in the North American "pop-top" space:
http://reimoamericas.com/van-concept.htmlIf I recall correctly this one seemed to be some entrepreneurial importer who has arranged a partnership with Reimo to represent them in the States. They are actively exploring Mercedes Metris conversions, and seem to be making some good progress:
http://reimoamericas.com/updates-posts.htmlhttp://reconcampers.com/I like the ambition of this guy's byline (given how neglected the small pop-top camper market is in North America): "The Future of Pop Top Camper Vans in the USA"
He looks like a one-man or few-person shop, with the Metris only on "future horizons," but it looks like he's done some pretty nice work on a Nissan NV200 conversion that is now complete.