If you plan to use the heat/air and eventually sleep in it, I'd either go ahead and get insulation added from the factory, or make sure it's easy to add later. Same with a roof vent.
Here is where I bought mine a few years ago (and it's in your neck of the woods) -
http://www.metrotrailer.net/arising-ind ... ailer.html Click on the "Pricing" link and you'll see the pricing for all the individual options, etc. Some options are quite cheap to add during manufacture. These guys were great to deal with!
The one I ordered/bought was 8.5 x 20 and included a v-nose, extra ground clearance, 15" radial trailer tires, a spare with mount, plenty of e-track (two strips on each wall and 2 strips on the floor, all the full length of the trailer and recessed), extra height, a roof vent with fan, extra interior lights with wall switches, two side vents that can be opened while moving, plywood interior sides, luan ceiling, insulation in the ceiling, 10,000 lb load capacity (two 5200 lb rubber torsion axles), diamond plate stone guard on front, all LED lights, pre-wired and braced/framed for AC/Heat if I want to add it later, and a flat floor (no beaver tail),
I bought this in 2011 and the cost was $6,650. At the time, this was the best overall deal I could find, and it was easy to get exactly what I wanted. I have been super happy with the trailer. In particular, the e-track is fantastic. It makes the trailer so much more usable. It's expensive, but worth it. The added ground clearance was also a great decision. If you get to looking, many enclosed trailers are really low. I was afraid I'd tear it up in rougher places, so the extra clearance has been great and no issue at all with loading anything. The big loading ramp makes it easy. The extra interior height is also a big plus. If I did it over, I'd go even taller.
Of course, the Pioneer is tall! It fits right now, but if I add a lift kit, I'm not sure it will. It may depend on how big of a guy I can get to hang off the back while I load and unload!
I've slept/camped in mine a few times. I've used camp mattresses, cots, etc. for several of us sleeping in it at one time. It works well!
Good luck with your trailer search. There are plenty out there to choose from!