Sounds like a cool project. Keep us updated with pictures, would like to watch the progression.
As far as a fridge I would think either a Dometic or Norcold would do just fine. Top style freezer with the fridge on bottom would seem to fit well in that rig. Most are pretty standard in that configuration and a 6 or 7 cubic foot would work well. I have had both MFG’s and my Norcold seems to work better. It cools down quicker and is very stable with temps, even in the hottest weather. As far as how much insulation I’m sure the installation manual details what is recommended and appropriate.
No need to further insulate but if it is in an enclosed cabinet make sure it can breathe. I, personally, prefer a 12 volt compressor driven refrigerator.
Not as critical when leveling the RV and no propane lines to run. Here is a link that has some 12v/120v with automatic switchover. My older Horizon RV has a 12Volt only and I am 100% satisfied. Not that much drain on the battery setup. (2- 12V batteries)
I'd say that this isn't a Class B. Wouldn't it be a Class C?
I wondered myself!
Maybe my ToyBox should be a B- or C+
Right now its just a box with a bedbox framed up and some drawer cabinets. My plan is to add an entry door on the right front with a one-step stairwell. The back has a roll-up door like a garage. It's heavy, noisy and I loose precious headspace in the back half. The garage door will come off and I'll build a 60/40 barn door split for the replacement.
When its complete I'll submit my Appeal for Classification. It may be that a new classification will have to be added to the alphabet
Seriously, thanks for the advice. Now its time to hit http://www.searchtempest.com/
Depends on what you mean by small. The two-door models are small compared to the fridge in your house, but are medium to large as far as RV fridges go.
Dometic makes the 3-way fridges I most often see in truck campers, small TTs and pop-ups. These are single door, sizes in the 2 to 4 cu.ft. range.
Most of the larger (6 to 12 cu ft) fridges with separate freezer compartments are two-way (LPG/120V). Norcold makes a 3-way in 6 and 7.5 sizes. There are also AC/DC fridges in this size, do not use LPG.
These are made for installation into a cabinet you build, there is no outside cabinet (that's another class of fridge) The N600 6 cu.ft. 3-way needs a space 53" high, 23 1/2" wide, 24" deep, and needs to be against an outside wall for venting, back of fridge surrounded by fire resistant materials. It operates best if the chimney can exhaust to the roof, but will install and function with wall vents for intake and exhaust.
If you are going to use 120V inverter power, you don't need 3-way, 2-way will do. The price difference for the 12V heating element and controls is about $100.
You will also find AC/DC fridges (or DC-only) in 2 cu.ft. to 4 cu.ft. sizes, for building in and as portables contained within insulated chests. The portables are usually 12V DC-only.