In my experience chocolate gouramis tend to come in with bacterial/parasitic infection re transit & dealer (transhipper/wholesaler/retailer) process ... if they were in your tank past a couple weeks without any symptoms of "crossed fins" (external parasites) or flared fins/then lifting of the individual scales (internal bacterial indicator) and good activity levels, it's likely they were fine.
I mostly feed frozen foods (Hikari as they irradiate & vitamin load, being careful to buy from knowledgeable shops) but find the chocolates (once settled) are quite enthusiastic about most foods.
I do hope you get in the Valliant Gouramis - I've long wanted them but have only ever seen S. osphromenoides locally.
I'm hoping your pH settles, tank is awesome!