I'm not sure I have any secret in getting a smoke ring. I'll admit that sometimes it's more pronounced than others, but I've never been really concerned about it. It might have something to do with the rubs I use, which are usually simple. (One of my favorites is just kosher salt and pepper, and then adding a sprinkle of kosher salt and coarse ground pepper before serving.) If I don't use S&P, I use a recipe that combines Hungarian paprika, brown sugar, kosher salt, garlic powder, onion powder and a bit of cayenne. I like the flavor of pork and think that too often the flavor of the meat is overpowered by a complex and heavy-handed rub.
IMHO, I think the smoke ring is more about cosmetics than taste. Marauder's answer suggesting higher heat might be a another method for you to get the infamous ring. Pork is pretty forgiving so cooking ribs at 250-275º would certainly be worth a try in your #2. I'd subtract out at least 30 minutes of cook time at the higher temps and then try the bend test for doneness.
I'm more concerned with that the TV guys call "the pull." Since I don't foil my ribs, I want them to pull cleanly and completely off the bone during the first bite. The method I described in my post above is my "secret" and I have a pretty good reputation among my family and neighbors for the best ribs around. I know this sounds conceited, but in S. Florida, there is only one restaurant I'd eat in and order ribs where I think they're on a par with mine, and that's Tom Jenkins in Fort Lauderdale.
One last thought is what wood you choose. I usually use a piece of hickory and a couple small chunks of fruit wood, either apple or cherry. Remember, too much wood does not equate to more smoke flavor, and in fact, it turns the meat bitter.
Sorry for rambling. I hope this helps answer your question, tbrtt1.