I've been using Apache cases from Harbor Freight, and they've worked out really well for me.
The Apache 1800 holds approximately 25–30 sticks plus a Humidipak, while the larger 3800 holds around 75–90 sticks with three Humidipaks, depending on cigar size.
I've organized my collection by brand, with separate cases dedicated to long-term aging. This makes it much easier to keep things organized and find what I'm looking for without digging through everything.
As for tracking inventory, that's a different challenge altogether! I think the biggest hurdle with any tracking system is keeping it updated as you smoke cigars or add new purchases.
If you decide to develop software, I'd love to see something simple that tracks brands, sizes, quantities, purchase dates, and aging time. Most importantly, it needs an easy way to subtract a cigar from inventory.
The best system in the world won't do much good if keeping it updated becomes a chore!