blakamin: You will still have to flash a PG58IMG.zip because it's the latest firmware and ICS will just boot-loop without it, but you can pick any of them.
That was the confusing part. Presumably I don't have to do that if I flash a custom ROM like Insert Coin?
It's just I have seen many guides about custom ROMS and none mention the PG58IMG.ZIP file needing to be flashed.