I currently have a 200 Gallon, about to be upgraded to a 12 x 4 x 2 Foot (yes that's still your 200 Gallon Simon). I am basing these whole tanks on my 2 favourite oddballs I'd say. Bichirs, currently only got 4 but will be upping that number, and datnoides, only got one Microlepis at around 12", but I'll be upping that number too.
I have also had a thing for Elephant Nose' since about 7 years ago I got a group of about 6 in a tank, but |I only had them for a few months and had to get rid of the tank. I have just today added the first fish to a 100gallon I have set up specifically for a group of 7+ Elephants.
If I had to pick, I think I may actually just edge towards a good sized group of elephants, fantastic fish.
I'd be interested to see how the elephants get on because been thinking the same about them myself. Theyare great fish