Sprocket depends on where you live and how much off roading you want to do. I've only tried 50T and 44T, but from what I hear 47T is a good compromise for somebody that's like 60+% street and 40% off road. You would not want to climb steep hills with anything lower than stock, but for just cruising or easy riding on offroad trails 47 should be fine.
If you wanna go to 44 you'll drop another 400+ on the engine speed, which makes cruising at 45 mph nice and smooth, the bike's optimal cruise speed. 50 is alright, 55 gets up there and 60+ is pretty fast, but thankfully 1k lower than stock. Only problem with this gearing is the lack of 5th gear power, it feels almost useless and if you go up on any kind of hills - forget about it. Other than that and take offs needing a bit more power, 44T is pretty good for the street.
If you wanna go with 47 and you don't mind taking the engine cover off, you might wanna try 15 up front for 15/50 instead. It's a just barely a little bit taller of a gearing than 14/47 but I've heard many great things about it too, plus a bigger front sprocket is supposed to be better on the drive and the chain. If you think you'd rather go for 44, might wanna consider 15/47 too for the same reasons, same gearing as 44.