I bought my '07 Taco with the full intent of buying a shell and building a sleeping platform. I did my homework, and on the advice of many, I bought an ARE. I went with the commercial unit. ARE calls it their DCU. Since I couldn't find any reviews on them, I'll add my 2c.
Buying all the options ala cart was awesome. I got an exact price for every option, figured out if it was worth it, and then decided if I could do it myself for cheaper. Things like lights and racks, I did myself and saves lots of money.
The canopy was reasonably priced: Something like $1100.
Side doors are a requirement. After owning a canopy with and without, I will never own one without again. Make sure your has them. I got a slider on the pass side and the door on the drivers. If I did it again, I would do doors all around. They can be opened 1" at night for vents and are more secure than the slider.
The best thing about this canopy is the security. With solid metal doors and real latches, it would much less tempting than a standard fiberglass canopy.
The con was the build quality. The construction was far inferior to what I was expecting, especially with the rep ARE has. There was cutting oil and alum chips all over the interior from them drilling/riveting the skin on. The welds looked horrible and the trim is poorly designed and installed.
If I had to buy another one, I would definitely get a commercial one, but it wouldn't be made by ARE. A gemtop or other highend commercial would be worth my money.