We did local pickup from a Melbourne ebay seller - Infrared Sauna items - Get great deals on Rooftop Tent, Camper Trailer items on eBay Stores!
The annex is definitely good for changing etc and you have a good point - there is a height limit. Double check with one of the sellers, but I'm pretty sure the ladder and annex are limited to 2.1m. You could maybe push 2.2m but past that you would need ladder and annex extensions which you can also purchase. Ours is currently on a stock height D1 so we were fine. I'm guessing yours will be higher...
Still happy with it. We used it again over NY when we got a bit of rain overnight. It wasn't heaps of rain but certainly no water inside the tent.

