1. Side entry allows a lower step into the TC and easier access when towing. We have a rear entry door and tow 2/3rds of the time - I don't mind climbing on the tongue when we make stops, but my DW does.
2. In our small TC, a wet bath makes sense to save space. If you get a larger TC, a dry bath is more convenient since you have place to hang wet things without taking over the bathroom.
3. You will need to run an extension off your hitch to tow. If the total weight is under 3000 lbs and you have a Class V receiver, a simple extension with triangulated chains will be fine. If you want to tow more, go for the SuperHitch with SuperTruss so you can use a WDH.
4. A 2000w generator can be used, but you must be careful to select a low power air conditioner. I prefer a built in unit due to the convenience: I do not need to haul additional fuel or generator somewhere, It is push button operation from inside and LPG does not gum the carburetor like ethanol gasoline when you let it sit.
5. I back the truck under TC myself. It does take practice, but it is easier each time you do it.
6. I watch my bed opening and keep it close on the driver side. If I use this as guide, the jacks and other side clears.
7. Since you have a custom bed, I would not attempt to use the Happi Jack system that attaches to the bed and bumper. Torklift bolts to the the frame and is typically a no-drill setup. Once you decide on the tie down, shop the Internet for pricing and see if the dealer will give you a good bundled price when you purchase the TC.
8. The draft on a TC is similar to a fifth wheel, so do not expect better mileage. If your combination is lighter, you will pull hills better and have better acceleration. I am at the same GCW with my TC and enclosed trailer as I was with toy hauler, so see little mileage difference unless driving in the mountains without the trailer.
9. I like my Arctic Fox, but they do not make a side door model (which might affect my next purchase). Look at Host, Chalet, Lance and Eagle Cap for large dry bath side door models.
The larger TC's will have a basement (sub floor). This area will contain storage and holding tanks. Some models build the floor over the wheel wells which will keep the center of gravity lower, but will reduce space for tanks and storage and require steps up to slides and the bath. Other models build out the floor above the rails. These floor plans allow for a flat floor and large storage at the expense of taller overall height and higher CG.
Host Mammoth 11.5 on Ram 5500 HD