Imo Excalibur is the best for most if not all tropical plants that they sell.
First time I went there, they had a tiny lychee in a 3 gallon with 3 fruits on it. Plus if you buy them from any random place you could get one that is not grafted or air layered, which means that it will take 10 years or more to fruit.
In regards to the original question, I too am very interested in knowing if a Longan would fruit in a container.
I’m sure they have a great selection but the customer service is terrible. Every tree that I purchased they are either in a three or 7 gallon container was falling over and belongs in a container smaller than that. I’ve emailed multiple times, I’ve called regarding 2 Jackfruit trees that could not stand on their own and I could not see the graft, not a single person called me back or returned an email. They sold me papaya, lychee and Longan that were supposedly 3 gallons, but they were less than a foot tall and belonged in a 1 gallon container. Nevertheless, it’s better to go to other nurseries.