After taking a bit of a break, I've had one of my friends who's a woodworking hobbyist start building out the walk-in for me.
Went with tongue & groove Mahogany bead board for the walls and ceiling.
I seasoned the Mahogany with distilled water and after a few days, the humidity & temp settled into the low 60's and hasn't moved in nearly a month. I have a five gallon humidifier, but I haven't had the need to so much as unpack it yet.
I put a 72-bottle wine rack corner unit in that fit perfectly to the left of the door. My friend built a 24" deep bookcase style shelving unit as the primary storage area for the cigars. The shelves are 100% Spanish Cedar and he drilled out ventilation holes throughout.
Because the walk-in is somewhat narrow, I'm only really able to utilize one of the side walls for storage which is why I went 24" on the depth. However, at 24" I can easily go three boxes deep. While two of the shelves are adjustable, I have everything at the same height for the moment. To get a sense for space, there's enough between shelves to stack boxes of PCs nine high.
Here's what it looks so far ...
I was able to fit 4 marine coolers full of cigars, another half-sized cooler plus the contents of an end table humidor on the shelves. I need to do a lot of re-organizing to spread things out a bit, but I'd guess there's still 30%+ free space.
Next steps is for my friend to install a Spanish Cedar display shelf along the back wall that will line-up with the middle shelf of the bookcase unit. Beneath the display shelf will be additional shelving to the left and five or six singles drawers to the right.
Above the display shelf will be a narrow 7" shelf for jars.
Shilala made me a super nice Partagas sign a few years back, and that's going on the angled piece of the ceiling.
Need to watch the humidity, but so far, it hasn't budged. Might look into a couple small corner fans to move the air around a bit.
Will post some additional pics once it's complete, but I'm beyond ecstatic about the progress to date.