The top can be made by anyone who does simple woodworking. Usually a piece of plywood with laminate on top and some kind of edging. Some are made from Corian (heavy and pricey) or other solid surface.
Several of the RV parts supply houses sell posts and bases, some have the articulating mechanisms to convert to a bed, this company manufactures a rather nice wall mounted table lift mechanism to leave the floor open. You have to have a sturdy wall in that area however.
'03 Ram 2500 CTD, 5.9HO six speed PacBrake std cab long bed Leer top and 2008 Bigfoot 25B21RB.. Previously, 2008 Thor Freedom Spirit 180, SOLD! 2007 Winnebago View 23H Motorhome, SOLD!