The Near Eye Remote Display is AMAZING! It was originally created for rebreather divers, but is also now available in a stand alone configuration to mount on your regulator.
See all the specs and details here: https://www.shearwater.com/products/nerd-2/
This is the watch form factor you've been looking for! It's amazing in the tropics, has air integration, and a rechargeable battery.
See all the details here: https://www.shearwater.com/products/teric/