16.5" rims are specialty items made for very low profile tires. You're not likely to find a good selection of tread designs or widths with that rim size. Also, a 16.5" tire has a tapered bead seat without a safety locking groove, so if a tire gets even a little low on pressure it will go flat and separate from the rim. The height of any XX.5" tire will be the same as an equivalent tube type tire. For instance, a 16.5 tubeless will have an exact-height equivalent in a 15" tire. The same holds true for 16" and 17.5. 18" and 19.5, 20 and 22.5, etc. If you're looking for an equivalent-height tire for a 16", start shopping for 17.5" tires and rims. Yes, they might have a little extra room on the inside, but they will look weird and you won't have much selection of tread widths to choose from. They're commercial vehicle tires, not really suitable for a weekend cruiser with altered ride height.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!