What are the dimensions of your tank? Sorry I'm not used to the size of tanks being indicated by gallon's as we use feet and inches to indicate ours here in Australia.
The other thing is that dependant on the size of the tank would depend on the amount of Elephant Noses that I would add. I have an 8ft tank that has 2 in it. Yes they do chase each other around the tank but they are also able to go off and do their own thing.
As for tank mates, IMO definately BGK's, Clown Loaches, Asian Bumblee Catfish, different types of Corydora's, Plecostomus of some description and a couple of Humpheads. These are just a few of the many fish that I have in my tank and have had no drama's with them what so ever.
When you do add them try to get them young and or around the same size as I have found through my own experiences that they seem to have a greater tolerance of each other if they grow together.
Hope this helps.
Cheers,
Bryce.