Just catching up on your post. I advise going against keeping clown loaches as they grow to be about 14". I personally prefer tanks that are stocked with as few different species as possible and having a lot more of those few species. This allows the fish to show their true nature and they will feel more comfortable in the tank if there are more of the same species. I suggest having a large school of 30 danios and or barbs would look really amazing in that 180 with 15 of the same species of cory cat rummaging around on the bottom. Or having 20 or more gourami minus the danios and barbs though. I have seen a 100g tank stocked purely with plants and Pearl Gourami's and it looked so amazing I didn't want to take my eyes off of it.