Rockthis, I think you're going about this in the wrong way. Many people who are planning to get their first octopus want to put all sorts of fish and other animals in with the octopus, but it doesn't work.
An octopus belongs in what we call a "species tank" - just the octopus alone. There are a few small inhabitants that can live with him: a serpent star, a pencil urchin, a starfish, maybe some snails (if he doesn't eat them). This can be a beautiful and very interesting aquarium.
Once in a while it happens that an octopus accepts some other sort of other inhabitant as a tank mate - maybe even a shrimp - but this is iffy.
Many people end up having a number of tanks - In addition to my octo tank, I have a second smaller tank of invertebrates, which is colorful and entertaining. So eventually you may have more than one aquarium, too.
All the best,
Nancy