Biggest issue is you'll have to get quotes and the whole contract Shennagins with finance if it's over 10k (maybe 25?). And they normally want that shit 2 months ago for end of FY purchases. I think pretty much anything is fair game as long as you can justify it as functional.
I've seen done:
Watches, coolers/lunchboxes, sunglasses, nice to have uniform items (better boots, undershirts, OCPs), knives, headlamps, hammocks, sleeping bags, morale shirts, massage chairs, travel bags (rolling and duffel), cold weather gear, sq bar renovations, sq facility renovations, software subscriptions, and more I'm sure I'm forgetting.