hey man, I think this is a cool stocklists. Dempseys are WAY UNDER RATED IMO. Just because a fish is common does not mean its not still a nice fish to keep. I also still really like Tinfoils (schwanfeld barbs... the ones with the red/black fins.
I personally would skip the shovelnose ... it will inhale everything you own eventually. Plus, just my personal thing... I don't like the way they look. I just have a 10" Tigrinus die on me, and ya know what, can't say that I miss him. My various Synodontis and P. granulosas have way more personality and more interesting, even if they are not as expensive.
The eels are great. You will love them as the start to get big. I have two LARGE ones in my 720 gal and they are great. Another fish you might consider since you like the Balas and the tinfoils are Yellow Finned Chalceus. They are a little squarer and heavier than the pink tail chalceus you normally see.. not a pointy nose. ANd their pelvic fins (I think) are yellow. Tail still a DEEP RED if your water is good. They look great when they get large, nice big scales and look good if you have 5 of them in a group.
Another possibility: Snook (Red bay snook). Or 3-4 dats.? And how about a big long armed (blue armed) prawn for some style?
Have fun... and I agree with what others said, do the research, don't be afraid to order fish online from REPUTABLE sellers and get WHAT YOU LIKE. I have a large tank like yours, and I have some real oddballs, some nice "expensive" fish, and a few real common fish that Ijust really like. Don't talk yourself into getting what other folks say is cool (that is what I did with my tigrinus.... never liked the fish, bought felt like I "had to have it".)
Good luck
