In NZ we are using the Bosch POF 1200 router. Bunnings has them, and there are instructions for hacking it here on the forum. Ours has been working fine for a while.
However, I noticed that Bunnings in Oz isn’t listing them. That’s curious.
You could use almost any router, but you need to be able to add the motor drive for the Z-axis (it can be made to work manually, but you don’t want that). I have looked closely at a lot of routers, and to be honest they all look like they were made in the same factory, just shot in different coloured plastic. If you look at the photos for modifying the Bosch you might be able to see if you could do the same with a slightly different model. For example, the Ryobi 1600W plunge router at $149 looks very similar.
I wouldn’t recommend buying an expensive router. You have to hack on it, so your warranty will be void, plus you’ll be using it for longer sessions than you would manually, so it’s going to wear out sooner.