I understand your desire to have a fruit tree and I'd suggest a citrus. I have a few in large containers. They require more water but the size will be manageable and they do produce fruit. I grow a Satsuma, a Kumquat and a Lemon tree. Used to have a lime but struggled with mealy bugs and decided it wasn't worth the constant effort.
I also have no experience but have seen fruit trees that can be grown on a fence as an espalier.
https://www.google.com/search?...
If you wanted to, you could do tomatoes in containers as well as smaller varieties of cucumbers and many different herbs that would be suited to container culture.
Please keep us posted on what you decide to do... and
