I am wanting to a paint a mural on an already finished cinder block office wall. I am needing to know what would be the best paint to use. To offer the best durability and finish.

We are working on a house that had latex applied over oil. The new owners want oil paint applied on all the interior trim, doors, mop boards, etc. The house is huge and to strip all the latex off is going to be extremely time consuming and expensive. Are there