What are the tank dimensions & how many of each species are you intending?
(note most of the "Chocolate" gouramis do better in shoals of at least 6 - 10 individals but also sufficient space for hierarchy/territory)
I have 12 - 14 Sphaerichthys osphromenoides & now that they are well settled in the tank, "shy & retiring" are not exactly how I'd describe their behavior.
Initially you may want to include some "dither" fish, perhaps a micro-rasbora ...
I started with a group of Trigonostigma heteromorpha, which did fine as juveniles, but as adults they can clear the majority of the food within a minute or 2 & they would be looking about ready to explode when feeding sufficient volume for the chocolate gouramis to also have rounded bellies. (I've just recently removed the harlequins, the choco's seem happier without their presence)
I just do clear water (typical of some habitats), tap is soft & acidic & tanks run ~ pH 6, planted (low level CO2, not particularly dim, though again I'm careful to transition new fish) with wood so lots of hiding areas - tank can look completely fish free or full of choco's.
I do 50% - 70% water changes once or twice weekly, they always seem to appreciate the change, though they disappear during the actual process.
I recently added a pair of Parosphromenus 'Unknown' they are definitely less visible than the choco's (I meant them for the shrimp tank but the duo began shrimp hunting almost immediately - current tank has a few amanos & tiger shrimp that are rather bolder than the mixed cherries in the shrimp tank, also tank is much larger ...)
Seriously Fish provides some habitat & care details that provide a good baseline for keeping these fish.
