If you wanted killifish you could have a breath taking tank with all that space! If you investigate about peat filtered water and how to maintain the corect ph in the tank with water changes if you wanted you could have a large killi set up and with some luck they would breed regularly enough to give you new fish each year and from what i understand the eggs are hardy enough that they are relitivley easy to grow the fry up.
The chameleon fish, there are quite a few types so you would have to research which ever your lfs had in. There are the common ones called badis badis, or the scarlet badis aka dario dario and also a blue badis but i dont know the full name of this one. They do well in very peaceful slow tanks, I think I would say with rasboras rather than tetras, barbs and danio, because they are generaly calmer and much more timid than the other schooling fish, the smaller ones like harlequins, espes, or even the dwarf red ones like pheonix, sparrow, eyespot etc these are a little rarer though. With the max size of the chameleon fish at around 2-3inches, the focal fish would be small so i think that you could also add in other small timid feature fish like pygi or sparkling gouramis, again though small very bright and colourful and not so obtrusive as to scare the chameleon fish. I think other good tank mates would be some kind of catfish like a cory species or maybe a few larger quiet bottom dwellers like banjo catfish or humbug catfish, maybe a smaller plec species a nice one for that size tank is a king tiger pleco gets to six inches and really nice colouration not sure how it would mix with the other fish but i understand it is a peaceful plec and as all the fish are small no risk of slime coat sucking. Or instead of cories how about dwarf chain loaches, very cool looking fish but can be expensive very peaceful and they stay small and school tighter than cories.
If you went for angel fish I wouldnt get either of the abouve mentioned fish because my angels are quite agresive and they often are again with these in that size tank i would make them the feature fish and add schools of tetras or rasboras around them, along with some catfish for the bottom. Or you could have hatchet fish if your tank has a hood they jump a lot but are usually okay in reasonable sized schools, if you say got 10 of them it would make them feel safe enough not to jump, there are many kinds available though three more commonly each species differs in size from 2 inch to 3 inch.
If you like angel fish as an idea how about one of the more peaceful south american cichlids as feature fish in a similar set up for the angels. Firemouths, festive, keyholes or rams can inhabit community tanks quite safley. The rams are the smallest staying around 3 inches, keyholes (my favorite) get to 3-4 inches average but some have reached 6 inches in show tanks. The firemouths and festive's usually grow to 6 inches though ive heard of some getting bigger, the fire mouths are probably the most agressive of all of them but mainly only get agressive around breeding season. An other option with south american cichlids are the convicts and have a breeding colony not sure about any tank mates in this though so it would depend how much you liked them.
With a tank of that size you could also do african cichlids as well though I have no experence with that but there are some amazing fish with them but they need a lot of research into each species. I saw some white labs the other day that were amazing! I really wanted them but i know i cant lol. I know that they need a different substrate to regular tanks to raise the ph and also they need extensive rock decoration to create caves at all level of the tank. I think this would suit you as you said you liked the colours of kilifish and african cichlids are often compared to marine fish for colour and vibrancy.
The list is endless lol hope ive helped
If it was me btw I would go for the chameleon fish tank. I would try and get hold of a pair of each type the regular, scarlet and the blue, a few pygmi gouramis probably around 6 (they dont school but they do squable a bit so its best to have biger numbers) Them add in a few schools of the dwarf rasboras and also around 8 chain loaches for the bottom. The dwarf chain loaches would be the biggest fish at 2.5 inches each. With a good stock plan that could be a very bright peacful calm tank.
I have a 55 gallon tank that I hope to stock some day with some tropicals. I am still trying to decide what to get. I really want 1-2 angels 
, but I am not sure. I also read an article in a magazine about chameleon fish, and they are really beautiful and interesting. But I really love killifish and all of the different color options and patterns. What do you thing would be the best idea for my size tank, or what fish do you just like better and why?
Any info on tropical fish that you enjoy will be greatly appreciated. 
i have keyhole cichlids that do fine with them in my tank and also a pair of rams i have a school of danio a weather loach and a syno catifsh along iwth some cories and a bn plec