I recently took delivery of a Queen Anne Macadamia from Sow Exotic and was really happy with its condition.
But not long after the fact I stumbled upon a place called Brackin's Macadamia Orchard in Plant City and I suspect that they might be the actual growers for several retailers of that tree in FL.
From the Brackin's FB page it looks like they have regular tours/sales/tasting events that might be worth a look if - like me - you happened to be searching for something besides the more commonly available Beaumont and Cate varieties.
On a related Mac Nut front, while I was searching for my tree, I discovered mention online of the late, lamented George Anderson Arboretum - the guy who seems to have been the Godfather of FL Mac Nut propagation until his recent passing. His operation was sold to a gentleman named Cliff Mohr, whom I had the good fortune to be introduced over the phone a few months ago. Cliff also spoke highly of the Queen Anne tree and that sort of sealed the deal about what I would buy.
Brackin's doesn't ship, BTW, so having the chance to see their trees first hand might be worthwhile.