If you are thinking of using either one on a stock, or near stock 883, beware they make it easy to lug the engine. Pulling off from a dead stop, on any grade gets tricky, requiring a lot of clutch slip.
My 883 is stock in bore but its cammed and have a tuneable ignition and hyper charger air cleaner... When I ride in a pack at 80-90 mph my rpm is very high.I'm trying to decide which sprocket is right for me
Decide how much of your time is spent at 80-90 mph, then how much is spent at lower speeds, such as how much time do you spend around town and such. I think, if you go bigger than 29-30 you'll be sorry, because of the loss of lower speed usefulness.
Even tough you have "cammed" your engine,(you don't say which cams), most cams add power at the higher RPM range and you could be gearing down below the power peak, defeating your objective. Make sure you keep the stock cog, in case you want to go back to it.