I had my present and last roof installed at "osage van conversions" in Linn, MO. They are a bit pricey now and took longer than agreed; I won't go back. I had another van done at "Malibu" but they are now out of business. Expect to pay about $2000 for the installation and minor frills such as a partial liner. Door height extensions will be more for the roof style and even more for the door extensions. Companies that specialize in vans equipped for wheelchairs may be a good place to look for the latter type of roof.
Start your raised roof research by contacting the dealer from whom you bought your van. Most every large dealership sells converted vans through contract with one or more conversion companies. Your salesman might give you a contact name at a converion shop and you can go from there. I think you might be better at a small facility that does not do assembly-line work like the huge outfits in Elkhart, In. Specialty work like we want, might be a bit pricey at those shops. I've been told that "turtle top" of Elkhart has a good price on roofs.
If you want the taller doors only to increase cargo capacity oppportunities, I suggest you determine if your carrier will have enough tall cargo to justify the added cost. With FedEx Custom Critical, I'm guessing I loose less than one run a year because the freight is too tall to fit witout breaking down a pallet of cartons. When that's the case, I get dry run pay and am up next for the next load. If a taller load can be placed in the van, we only get van pay so we get no extra money for hauling tall freight.
Freight size/weight policies for vans differ from carrier to carrier; some pay more when vans carry bigger/heavier loads, but most of the larger carriers do not pay more.
Slightly off topic, but let's take a reality check here. When we van operators are willing to take "C" freight for "B" money, we lose in the long run. Van (B) loads were originally defined as two 4 foot cubes no heavier than 2000 lbs. As we were willing to take a little more, for the same money, the carriers stated redefining a "B" load, so that now they require us to take 2500 lbs for "B" money; one carrier is 3000 lbs. As more and more drivers are squeezing three pallets into a van, it's only a matter of time before 3 skids and 3000 lbs becomes the "B" standard. We'll get little or no more money for this added load requirement and our expenses will rise in proportion to the extra weight. Our vans will no longer last 5-600,000 miles so we'll have to replace them sooner.
Off my soap box now. So, Chad, get yourself a raised roof and enjoy it for the added creature comfort. Good luck with your search for the best one.
Terry