I've only heard good things about the Aussie system, I would go fo this.
It seems the best option with probably a lot less work than TF sub frames.
You could always get the sub frames with a TF fitted to them
I have leads on a couple of TFs that are coming up for end of life, one is about 40 miles away or there is a cheaper one about 100 miles away but this one is the same colour so could also donate some panels.
Whatever I do I need to drop the front subframe as one of the lower wishbones is shot, the other looks like it has been replaced before I got the car 6 years ago.
TBH the continued use of hydragas is not really an option anymore, I've spent the last 6 years worried about it, fixing it or bottoming out so something needs to happen.