I have not tried Rollinia yet. But if you already have atemoya
then sugar apple will not be much different, being one of the parents of atemoya. For variety, I'd go with the Rollinia.

Rollinias are fairly easy to grow; they do need warmth and benefit from protection from strong winds.

I have the KM Sugar Apple, Green Sugar Apples, Cherimoyas and Atemoya.

I prefer the KM (red) Sugar Apple out of all of them. They are all delicious, but the red SA is such a beautiful fruit as well as being tasty. People are willing to try it, due to it being pretty. Lots of people who are not used to trying "different" fruits find annona fruit to be ugly.
I don't agree, of course.

Pine Island Nursery has healthy plants that will produce for you quickly.

Here is a photo of one of the fruits on my tree last year.

I have not tasted or grown Rollinia.

Lisa

Many thanks, Siafu and Lisa. One thing I guess I forgot to mention is that I'm also thinking of trying a Soursop, though I worry about how big the tree would have to get before it would fruit. And I see that these days there are options between seedling, "fiberless", and a sweet variety called "Dulce" soursops.

cattman- I am also growing sugar apples a little south of Savannah. I have tasted Rollinia and was not really all that impressed with the fruit. I think the sugar apple is a much better fruit.

I also second Lisa's recommendation of Pine Island. They are a great place to deal with.