Stock gearing is 15/110,I prefer 15/113,but others that do more touring went the other way and geared up. RK- GB50MFOZ1 is the chain that comes stock,EK is good,DID is good. I just replaced my chain and sprockets myself, Sunstar wich is a good brand for sprockets and I went with a Tsunami o-ring (Sigma) chain.
I'm not much of a mail order guy, I have a buddy who owns a bike shop. If there are any small shops in your area that you can look through the catolog(like Parts Unlimited) you can see the diferent chain strength and cost. My chain list at a bit under $200,but I got it for $120. I'm not sure what the sprockets cost, I just run a on-going tab.I'm guessing around $50 for the pair? I did'nt look at the price,just told what I wanted to order.