There used to a winery in the main drag of Tanunda in the Barossa that specialized in nothing but fortified wines. My wife and I and some friends dropped in there many years ago. They had Chardonnay's, Shiraz, cab savignon fortifieds, you name it. They are falling out of favour in today's market in preference to table wines.
Grant Burge still has a fortified wine store in Tanunda, but I'm not sure it is the same one. I just checked out their web site, it's the same building, so may be the same.
Guess I'll just have to visit them again and report back here with some recommendations.