I've been through this a few times. I used metal guides the second time, but the chain broke less than 20,000 k after. I was far from home, so I never got to dig into the engine to determine the cause. On my current engine, I did the chain, tensioner, head, etc, about 50,000k ago. I went with OEM for the chain, guides, gaskets, tensioner, and ENGNBLDR for the head. Service from ENGNBLDR was excellent. I tend to have the valve cover off about twice a year to at least inspect, adjust valves, etc.