I'm not sure if you will be able to find them in 16mm, but I have heard very good things about NATO straps and their high-grade cousins.
I usually just use standard leather straps, so I don't have any personal experience with these, but they look promising.
Real issue NATO straps are basicly a Nylon ribbon that is ultrasound welded around good quality buckles and keepers. It is for all practical purposes indestructable and will hold onto the watch even if one of the spring bars fails or falls out. If you choose these make sure you get an actual issue grade one, as there are a lot of junk bands with this basic design.
Other than the NATO straps there are also Waterbourne and Rhino straps that are essentially the same thing but made of heavier stuff.
Figure on about 20 bucks for a NATO and twice that for the others.
Many people also sell a nice Swiss rubber strap that comes on a stainless deployant clasp. They are smooth on one side and textured on the other. I got one of these to put on my beater watch and it has worked out great. Very comfortable and strong, still looks like new after being repeatedly soaked and beat up. Depending on where you buy they go from less than twenty bucks up to thirty five or so.
If you're handy with a blade you can make these fit any size watch since they won't fray or unravel if you cut back the lug area a bit to get some clearance.