Following on from my last query. The piston rings I'll be fitting will comprise of two compression rings and one complete oil control ring i.e not a control ring consisting of two rings and a separator. What's the correct orientation?

Read the information sheet that came with the Pistons, if you haven't got one ask your piston suppliers.
Failing that look at the packaging for the rings.

The rings are normally marked top as they'll be keystone shaped or tapered.
Ring gaps will be as far apart as possible so 120 degrees from each other.
Unless you're experienced then get a ring expander, otherwise you WILL break them.
Also use a stone to put a very slight radius on the outer edge or the ring gap to stop it digging in.

Piston rings rotate on the piston when running, around 75rpm at normal engine speeds from memory, just make sure you get the correct ones in ten correct place and the right way up!

If you need a ring expander I have one that I am unlikely to ever need again.