"If you want to put one way metered valves on each oiling point..." - There should be no "if" to this. If you don't, you have no way of ensuring oil reaches all the oiling points anywhere near equally. In fact, you'll likely find some points get over-oiled, while others get no oil at all. And, without check valves, oil will drain away from the higher oiling points, and into the lower ones, so next time you try to oil, lots of oil will go to the low points, and little or none to the higher points, since it will take a lot of flow to re-fill the higher lines. It helps a lot to use large tube (6mm is good) between the pump and the manifolds, and 4mm from the manifolds to the oiling points.

Regards,
Ray L.