If you want your plant to grow above the balcony edge, you need one that grows tall but is pretty resistant to wind and sun. How about bamboo in a planter. They grow tall and do a great job (all year round) of hiding what is next door. They are fairly low maintenance and self-sufficient once established. Cons: They do cause a lot of leaf drop - some species look pretty awful in the winter... but you can find some that are beautiful. Go for a clumping bamboo.

altering my garden with new design

I would suggest using money plant (even picture above has it on top shelf) also spider plant is a good idea. these plants will add beauty also for air freshening.

Same happened to me and I still regret not saving it on time. I later realized I could have just cut the healthy parts and propagated it. Can find a lot of video and material about propagating from leaves and stem cuttings.