First of all, I have no practical experience in knife making, so my opinion about knife making is mostly based on what I read on the internet.
I like things that are as functional and durable as possible, and require as little maintenance as possible. That's why I would choose plastic sheath material. Within this, I would choose Boltaron, because as far as I know it is better, more durable than Kydex (and especially more durable than Holstex), it starts to soften at slightly higher temperatures than Kydex and becomes less brittle at low temperatures. Within Boltaron, if you can get it, the 4332 version would be better, but 4335 is also good, the latter is perhaps easier to get and a little stronger, but it can withstand more extreme temperatures a little less and is less tough.
For the handle material, I would also choose G10, it is very durable, easy to obtain, and available in many colors.
In terms of steel, I think the most balanced (wear resistance-toughness) is CPM 3V, and among stainless steels, MagnaCut, so I would choose these first if the knives are intended for harder use, but wear resistance is also important. Of course, proper heat treatment is essential for these steels as well (e.g. appropriate low temperature tempering cycles, and if greater hardness is required, cryo treatment as well).
And I wish your company and you the best of luck!