Out-of-round will be easy for the machine shop to measure. It it's that bad, you'll need a rebore anyway. I'd be surprised if it was that bad at all if there's no lip on the bores. Go ahead and get the professionals to do it right, and be sure to clean the block yourself later on.

The general (Internet, for what it's worth) consensus is that the Rover V8 doesn't like synthetics and doesn't need them. The cam needs lots of zinc, or as it's often called, ZDDP, which is why Penrite oils seem fairly popular. The V8 seems to really needs lots of oil changes, otherwise they gum up pretty easily and then the cam is the first to go.