I have built several cigar box guitars and other related instruments and I think you can make exactly what you want. I have used sturdy cigar boxes for bodies as well as 1/4” and 1/8” Baltic Birch plywood from a hobby shop and other found materials.
The first couple of photos are of one that I built using some scrap cedar fencing and a license plate for the top. Small, lightweight and sturdy. The second photo is a funky reso using 1/8” Baltic Birch plywood. They can sound amazingly good considering the size and materials.
I use 1x2 maple for my necks, shape them with a spoke shave and glue on a 1/4" oak or maple fret board that I make to 24” scale. You can use the neck through method which is easy or a bolt-on which I prefer. Traditionally they are 3 or 4 stringers and can be fretted or slide only if you prefer not to go the fretted route. 6 strings would of course require some sort of truss rod where as the 3 and 4 stringers seem fine without.
Most parts are available inexpensively at cbgitty.com (no affiliation) and there is lots of building assistance at cigarboxnation.com. Good luck and have fun!
