Sorry for the late answer but I just joined this forum.
I don't grow passiflora myself but you might want to check out Rainbow Heights Nursery down outside of San Diego. Their current website doesn't list passiflora but it was discussed on gardenweb (now Houzz) as a breeder and wholesaler of passiflora. (
Best Edible Passiflora source (and varieties) in SoCal?)
When I was starting out, I got a lot of my trees from the Silbers who have both cherimoya and passiflora. Alex Silber is extremely generous with his time and information but he
is expensive. Since you are looking for little plants to bring into Corsica, he might be able to help you out without it costing too much. He is north of LA in Granada Hills.
Papaya Tree Nursery Plant Complete List
I have not been to Ong Nursery down in San Diego, but fellow members of CRFG find it a fascinating place. Basically a backyard operation. Again, don't know if they have "small" plants.
Trees
Roger and Shirley Meyer used to sell wonderful trees also but Roger just died so I'm not sure what is going to happen to their nursery.
The irony is that most of those cherimoya you want are actually available at our big box stores (Home Depot, Lowes, Costco), though probably not in May.
Availability
I was just out at LaVerne Nursery, in Piru, CA, a wholesaler that supplies those stores and got a beautiful Vietnamese cherimoya. I also have Fino de Jete and El Bumpo which I grafted onto seedlings I grew from Lisa and Bays seeds. I would be glad to give you scion wood of those if you have any interest in grafting when you get home (I am a totally novice grafter but all my cherimoya grafts took so I am guessing they are very forgiving)
Since this is a banana forum, you might do better asking your questions at either CRFG.org or the very active LA and San Diego chapters.