I'm currently cycling a Dennerle CO2 system with true-aquatic plants (after great help from a thread I posted on Thursday, with over half the plants identified that were bought on Wednesday as not being aquatic, took them back, manager was very helpful in replacing them and convinced me that CO2 was the way forward).
Stocking plans are focused around a lovely pair of Opsarius Pulchellus (Green-Barred Danio) they have. If I cannot source a few more of them, I'm tempted to try and get them to "play" with two or three Giant Danios. Other fish being considered are Dwarf Neon and Celebes Rainbows; Sterbai Corys; possibly Celebes Halfbeaks.
For some reason, very few loach species appeal to me by looks, but I do like
Horse-faced (although I'm concerned at potential 20cm size)
Zebra (can sometimes be territorial amongst themselves and other fish)
Dwarf Chain (rather pricey and concerned about how they would do in hard-very hard water, pH 8.1 and dropping due to CO2)
Kuhli (lovely banding and the eel-like appearance, but have reputation of not being seen in daytime and getting into silly spoits in the tanks setup. Was wondering about ~10 for my 240l, but unsure)
Indian Redtail Squirrel (still has the eel-like appearance, but unknown about its habits relative to Kuhli)