Any other open Indoor Navigation Services I should be looking at for inventory tracking?
I've had success putting 18650 cells and then 3d printing cases for these: https://www.amazon.com/Makerfocus-Battery-Shield-Raspberry-A... Battery last long enough for peronal tracking around my house, but likely wouldn't be long enough to track the thing for multiple days in a row without a recharge.
For inventory you could use decawave, but it would be pricey.