Why didn't you buy that Dodge 1 ton I mentioned a while back with the sleeper cab?
How about this? http://www.auto-rv.com/default.asp?area=browsedetail&adname=BK1080569D http://www.auto-rv.com/default.asp?area=browsedetail&adname=BL647057 http://www.auto-rv.com/default.asp?area=browsedetail&adname=BM1201030D http://www.auto-rv.com/default.asp?area=browsedetail&adname=BI4131815D http://www.auto-rv.com/default.asp?area=browsedetail&adname=BI4131883D An E350 with two rows of seats and a gooseneck might be nice, but I don't see them too often. I've seen retired E450 ambulances without the ambulance body for $2k or so, but the body just ends behind the driver's seat, you'd need to fabricate a rear seating area and close off the back from the weather. I've got enough 24oz fiberglass cloth to fashion a sleeper area if you want to work with foam/glass construction.