Which Selenicereus? For grafting and fruit?

[nitrogen]

I'm interested in this genus for two purposes:

1. Grafting

2. Beauty and Fruit

Can anyone recommend which would be best for these two purposes? I find many different types of these?

[2Deep2Handle]

Selenicereus grandiflora var. Cuba (smaller stock for smaller scions)

Selenicereus grandiflora (bigger for bigger scions)

Hyclocereus undatus Red dragon fruit (not the grafting one i beleive)

Hyclocereus ?? Yellow Dragon fruit (fruit and stock?)

Thats what im under the impression of anyway