A vintage 20" Stingray is surprisingly stout, and will support a 160 pound adult with a 30" inseam very easily. I know, because I once owned three of them. One was a Fastback, another was a De-Lux single speed with ape hanger bars, and yet another was an original with the solo-polo saddle. Back then there was no shortage of decals, correct color paint, reproduction parts, or highly skilled enthusiasts who would do complete restorations for the right price.
They were great for short trips to the grocery store or coffee house, and could turn heads where there were people who shared the same interest. Unfortunately, mine got sold because they weren't making me any money or reducing my transportation costs adequately. For that, I needed something that was reliable and cheap to fix, tune, and maintain. So, I ended up with one of the modern hybrids. These days, I get far more conversations when I'm on my Specialized Crosstrail than I would riding a 1962 vintage Typhoon.
Stingrays and their variants are great when you take them to shows and win prizes. Otherwise, it's a money losing proposition owning and maintaining one. Stingrays have also declined significantly in value in recent years since they had peaked in the late 1990's. I would opt for a Paramount, Colnago, or other classic that will hold its value and appreciate if taken care of.