Conversion trucks and vans arent just a Texas thing, their popular throughout the south. There arent very many conversion companies left in buisness anymore. Most conversion vans/trucks are purchased through a manufacturers dealership (GM, Ford, Chrysler) from a regional conversion company. You can normally add on anywhere from $5k to $10k to the trucks basic price, but that depends on whats added in the conversion and the price can get higher. Southern Comfort http://www.mcmvehicles.com/ is one of the few left in buisness that sells full conversions. Southern Comfort Auto Parts (I dont think their related) still sells parts for conversions http://www.southerncomfortautoparts.com/ They have access to parts for most conversion manufacturers, even some now out of buisness. At one time there were about 5 different companies selling a "Cowboy Conversion" so you'd probably have to look through your truck to see if theres any placards or paperwork left behind to indicate which company built it. Some of the better known names that built Cowboy Conversions were Regency (out of buisness now) and StarCraft. Even though these trucks/vans were sometimes double the cost new the resale on them didnt hold well and they normally sell at the same price as an un modified vehicle of the same material condition/mileage. An enterprising truck/Van owner with the skills to do wood and fiberglass work could buy all the parts needed to do a conversion at a local auto audio shop and Home Depot.