Regardless of who you go with, use assembly lube on the camshaft lobes & rocker arm lobe pads. And of course, adjust the rocker arm valve lash to .012" as the FSM states......THEN re-adjust them tighter after you have driven it some, if you have too much tapping. DO NOT go any smaller than .009" valve lash when the engine is up to operating temp......or close to it anyway.......it will cool down some before you get all 8 rockers adjusted, more than likely.
This has been what I have done for years, and I've never had any issues.
NOW......about the camshafts that several people have had where the lobes get wiped.......on the cheaper loaded Ebay heads, they are quite possibly using a cheap, China made cam......and the odds are good that it is not "hardened" as it should be to stand up to the pressures that the valvetrain can place on the cam. I have even seen this with crankshafts in these Mazda engines before. The ALUMINUM crankshaft BEARINGS wore into the steel crankshaft! No matter how good the oil & oiling system is, it won't keep it from destroying an inferior built cam or crankshaft.
Here are a couple of pics from the teardown of a JASPER engine (known to be a decent engine rebuilding company) that used an inferior new crankshaft in the rebuilding of this Mazda engine.......the engine actually made it 30,000 something miles before the clunking got too loud to ignore. This was in a friends truck that he bought from a older guy that had a local shop install a new Jasper engine into the truck, prior to selling it a few months later.
