Mac,
I bought my ATC Panther used and I think you will be very pleased with their product.
Mine had a furnace,sink and water tank, stove,fridge,and battery.
If I had it to do over I would just get a shell with furnace and modify it to suit my purpose.
I use an Engel 12 volt fridge in the truck cab as I found the 3 way fridge to be more trouble than it was worth. I moved the camper battery to the engine compartment along with the charge controls. Much better location and frees up storage space.
I don't use the water tank that much and would rather have the space for storage of water jerry cans. A plastic wash basin would do me just fine and free up a lot of space for storage.
I like the stove for heating water and would keep it although I do most of my cooking outside. The space where the water tank is might be able to be used for an Engel fridge. Check that you can raise the lid with the top down.
Solar is nice. I added a 65 watt panel to keep the Engel going.
I added two pull out tables which I like much better than the stock table. Check my posts to see some of the mods.
Keep it simple and light.
I view my camper as pretty much a tent on wheels with some additional comforts and spend most of my time outside.
Nice to sleep out of the rain and bugs, but not a house.
Dsrtrat
My basics are furnace, stove maybe, extra battery, and a place to tie flies out of the wind and/or rain then decide on the amount of fluff is needed to keep all elements satisfied. Thanks for the ideas and I'll look for your posts. Mac