Atc200s timing set

[207wheelin]

So my most recent 200s engine is back together and installed. Runs good, idles good, but it has a pretty loud tick. I'm pretty sure it's the cam chain. Even after a tension adjustment it's still noisy. I plan on putting a new cam chain on it.

Questions

Do you normally replace the chain and guides or do you do the chain, sprockets and guides? Do you change the lower sprocket?
Also what brand parts would you use?

Thanks for your help fellas
Much appreciated
207