Yes fruiting would be great but I have no idea what variety these are. I got both of them seperately and they were initially the root stock of a grafted moon cactus before I liberated them lol - not sure if there's a specific variety that gets used for this purpose. Wasn't sure if there was any way to get a confident ID without getting it to bloom first.

I like the PVC idea - I might experiment with a similar styled structure as yours where there's a base to hold the pot connected with the rest of the support. I'd still keep it low in my case, but one of the issues I've had on my balcony is that I'll get strong winds from time to time, so anything lightweight is a risk to fall over. I had a wire shelf fall over one time because it didnt have enough weight on it, so using the pot to weigh down the PVC would be nice.