Roll cage ordered.
What a minefield of information ROPS is!
A welded cage was my first preference, however given Queensland legislation now outlaws new registration of vehicles with full roll cages I have decided to go with the flexibility of a bolt-in cage. This will allow me to get the car onto historic plates legally and could help any future resale.
So I have ordered a AGI cage. Price is about $2800 delivered to Brisbane. I'm confident of my abilities to install the weld in base plates but will also have the assistance of Michael Harris of Promotive to ensure I don't bugger it up. The cage will be here in about 3-4 weeks.
Photos below are of a similarly finished 911 cage. But I will be getting higher spec side intrusion bars.