Re: Darn stubby legs ...
Your right about a grown man riding a 20" bike, It just aint right. I've been building bikes for almost four years now and the only bike that that looks even close to right is the 24" OCC. The problem with those is that the metal is way too thin throughout the entire bike. I've built about ten of them and have had to weld them back together more than I would like.
Just my opinion, Go with a 26" frame. You can chop it and lower it any way you want to get the LOW or lowrider look. With a 20 or 24" fork and a 24" wheel on back you could get it pretty low.
Anyway, Like I said, Just my opinion. Good luck with yer build.