I'm not really familiar with the loaches except the kuhli coz they get small. The oloaches might stress the eels. I wouldn't recommend the kuhli, or they might be fishfood for the other fishes that you mentioned. The goby is brackish and if ever you might convert it to fresh, you might also shorten its lifespan.
this is my idea:
A. 1 Fire/Tiretrack eel
Any bichirs species
Dragon Goby?
120g tank or above
B. The Spiny eels (Zebra, Zig zag yellow tail, Peacock)
Smaller Species of bichirs (senegal or albino version, delhezi, palmas etc) check http://www.polypterus.info/profiles.htm
Dragon Goby?
Ropefish
75g tank or above
this is my idea:
A. 1 Fire/Tiretrack eel
Any bichirs species
Dragon Goby?
120g tank or above
B. The Spiny eels (Zebra, Zig zag yellow tail, Peacock)
Smaller Species of bichirs (senegal or albino version, delhezi, palmas etc) check http://www.polypterus.info/profiles.htm
Dragon Goby?
Ropefish
75g tank or above