There will be some important issues with the fish mentioned in post #1, and they are not all compatible. I will try to explain.
First, combining gourami species is always a risk, much as combining cichlids, and for the same reasons. I won't get into that, but move directly to the Chocolate Gourami. This species has some very specific requirements that absolutely must be met; think discus, only even more so. I have kept and spawned them, two of the four species. The most common is Sphaerichthys osphromenoides (the one you mention) and I also had O. selatanensis which is identical in patterning except it has an horizontal creamy mid-band unlike the former species. Requirements are identical whichever species. Although the Honey is generally peaceful, for a gourami, it is still likely to cause stress for the chocolates so I really would not mix them; there are some other small gourami species that can work, but not this one.
Fish acquired will most likely be wild caught, and they inhabit peat swamps and blackwater streams in very densely forested areas of Sumatra and Borneo. Your very soft water is perfect. Warmth is crucial, no less than 80F, and never let the tank cool. This is one of those cases where water changes must use water as warm as the tank (normally slightly cooler water is good but not here). These fish are highly prone to skin infections, velvet and other parasites, and protozoan, and poor water conditions are nearly always the cause. Stress from inappropriate tankmates and/or the environment are also factors.
Plant the tank as thickly as possible, and have a complete cover of floating plants. Ceratopteris cornuta (Water Sprite) floating is ideal, but any other similar plants will work. I had the lower tank planted with crypts and Wisteria (Hygrophyla difformis) and allowed the latter to grow along the surface in some areas, and this provided another ideal floater, though the lower leavers tend to die off when the tops of the stems are allowed to grow this much in the light. Chunks of wood are also good, both for authentic decor but also the release of vital tannins. Dried leaves would be good. Light has to be subdued, so lower plants that can manage (like some of the crypts), or just the wood, is best.
This species is best in a small group, with a mix of male and female. Males are, like all gourami, territorial, but in sufficient space injury is not likely to result, and the normal on-going interaction between males is one of the joys of keeping this species. And with females present, they will readily spawn if conditions are to their liking, and being a mouthbrooder (female here) some fry will survive among the floating plants.
A 29g like you mention is the smallest tank I would suggest for the chocolates, and a group of 6-8. Tankmates are possible, though many recommend against it, but I found that the small rasbora species worked. Boraras species as you mention are fine, but in a larger group, at least 15. These will tend to remain among the floating vegetation. My chocolates, and I had six adults, did not bother the Boraras. The smallest of the "Harlequin" species, Trigonostigma hengeli, can also work but not with the Boraras in this small a tank. I had all these in a 4-foot 70g, along with a small group of pygmy sparkling gourami, but I would not include another gourami here.
Threadfin rainbowfish might be worth trying, a group of 8-10. My only concern would be the tank size, as this affects the behaviour of many fish and I am not sure how these two might react. But if you have another tank possible in case, it may well be worth trying. The blue-eyes, I am not sure which species...Brevibora dorsiocellata perhaps? If yes, these can work, though again the tank space is limited, and the temperature is pushing things.
I would not include the pygmy hatchetfish here; it needs some open surface, plus I am not sure how the chocolates would react to a fish in their space (the surface) so continually. Corys like those mentioned would work, except they cannot tolerate this warmth; 75-76F is max for the "dwarf" species.
One suitable bottom fish would be the banded dwarf loach (not the regular "dwarf" loach), Micronemacheilus cruciatus. This is a very nice fish, quite quiet for a loach, and I have had success with it in similar tanks.
Hope this is of some help, feel free to question anything. I'll attach a photo of the 70g to illustrate the sort of planting you want.
Byron.
/www.seriouslyfish.com/species/pseudomugil-gertrudae/
