When did things change from 108 links being oem and fitting a 13/47?
And this time I even checked to be sure an 'H' model is what is being talked about.
110 is used for 13/49-50 from anything I've heard. Consider that a 50t rear will require a different rear guide.
re: 'any junk o ring chains or sprockets to stay away from?'
You likely won't find consensus on this question. Maintenance procedures will have a huge impact on the life of any chain/sprocket combo. Someone using a not-so-good chain and taking excellent care of it will have an opinion that will seem to not jibe with someone else's opinion of that same chain.....them not taking care of it at all.
I've had excellent luck with RK (x-ring) chains. I prefer steel to aluminum, self cleaning to 'regular'. I've found Renthal CSSs (counter-shaft-sprockets) to fit much better than any other CSSs I've tried.
If you buy 112, make sure you have a chain breaker or other suitable tool to take off a couple links.
there is a place here that is called Princess Auto (Canada) not that you have one there but any auto supply store should have them, I bought a 10ft length motor bike chain, it's a little long but easily cut to size. If your looking for something a little cheaper that's the way to go. It fits great and looks just like my old one, minus the wear and tear. It only costs me 18$. I called my local dealer and they wanted 100$ for one on sale (little too much for me). It's meant to fit a 50t sproket. love it!!!
110 is correct - I put a Sidewinder chain and sprockets on all at the same time and have been happy with them. No noticeable stretch after a year. I probably maintain it more than average but that's me. I will tell you that the chain lube they offer is some of the best I've used. It clings to the chain but doesn't collect dirt and sand, and it cleans up at the car wash with soap and water. You have to keep the master link greased but I haven't noticed any tight links in any of the other links.
An o-ring chain is slightly wider than the stock non-oring chain which makes a tight fit through the stock chain guide. You can either buy a new chain guide through someone like FRP or modify the stock guide with some spacers.