Upgrading Tank

[Biulu]

Hi, I am preparing to upgrade to a 180 litre bowfront tank, basically for my 2 pears and 3 dwarf gouramis. Currently I further have 6 serpae tetras, and 3 cories. Does anybody have some good ideas of what else could go into this tank? Water here is around 7.5 and quite hard. Tank will be planted. I like colourful, active fish.

 

[orange shark]

get three more cories because they need to be in groups of atleast 6, and maybe add some neon tetras or harlequin rasboras

 

[Biulu]

I have been looking at congo tetras. What about a school of these fish, or would it be overstocked then? The tank is 1 metre long, and I read they need at least 75 cm.

get three more cories because they need to be in groups of atleast 6, and maybe add some neon tetras or harlequin rasboras

Actually I was thinking of getting some trilineatus. I love these fish!