Pereskia aculeata is beautiful, has extraordinarily nutritious leaves, survives whatever you can throw at it (i was reading your other
thread today about killing stumps and envisioned my Pereskias, or ora-pro-nobis as we call it, which have survived machetes, trampling, lime, leafcutter
ants, and probably will be here with the cockroaches and Keith Richards when we all shuffle off this mortal coil).
It gets beautiful flowers and theoretically can fruit (we don't get hot
enough here for it to fruit, by you it
should).
It should not be horribly difficult to find, as it seems to be all over Latin America and the caribbean, under many different names.
It also is an amazingly dangerous thorny, invasive monster that will definitely keep your goats out. Managed correctly, it could be a beautiful and fabulous ally. Or it could be your nemesis, like on my little urban farm.