If you're looking for one to assist in back support, then you need to ask retailers, if the seat has lumbar, thoracic and cervical spine support, and is therefore 'ERGONOMIC'.....
I googled Ergonomic recliner rockers...I think Jason does the most in this type of chair, so you might start by calling them and asking whether they make a specific recliner that is designed ergonomically. Matt Blatt also claims to have ergonomic design chairs, but I couldn't see anything like a recliner in that category.
Otherwise, when searching, include spinal support in the search criteria. Then go and try them out....it's the only way to choose a chair for comfort. There are several outlets for the Jason recliners and as I said, they've been in the business longer than anyone else, so they should know their marketplace. They may even be able to tell you if there is a therapeutic, or eronomically designed recliner....i.e. even with a massage setting..now that's my idea of comfort...lol
Another thing you could try is to ring the Occupational Therapy associations in Melbourne and ask if they have anything they might recommend as OT's...its a profession that deals specifically with ergonomic aids and therapeutic Daily Living devices so if there is such a chair, they would be the most likely to know about it. You could also ring up Medical, Therapeutic suppliers because they put out massive catalogues (which OT's often use) listing all manner of ergonomic aids including gel cushions, neck rests.....everything. The emphasis being ergonomic and therapeutic yes..not just comfy and stylish?