Well, I think it's settled, and not how I expected, either.
I finally was persuaded to get the 7.62 in 16". But, when I called my dealer, she was out of 16" models, but she had one 20.5" instead (she cannot get the .223 at all, she says). Funny, when I called 2 weeks earlier, she had a bunch of 16-inchers in stock and no 20.5 inchers, so it looks like her business is doing quite well. (That makes me happy, citizens buying guns, you know.)
So, I either get the 20.5" now, or wait a little longer for the 16 inchers to come back.
So, as I said, it's settled: I'm buying a 20.5" now, AND I'll get a 16 incher when they come in, AND THEN I'll get a Saiga-12.
Sound reasonable?
By the way, the dealer I'm buying from is:
http://www.ak-47man.com/SaigaRifles.html No harm in putting in a plug for them. They seem to have good service and prices, from what I can tell, plus a 3% discount for cash.