Hello and welcome to fishforum! Gourami like soft, acidic water, very different from Malawi! It's not quite as extreme as discus, but driftwood will certainly be just fine. Any ph between 6.0-7.4 should be great, and soft is good, probably around 4ish, although they aren't too picky. 78 should be a very good temp. While they certainly don't like heavy flow, they aren't very sensitive to it (unless they're trying to build a bubble nest and it keeps coming apart), so any standard power filter or something like that will be fine.
I'm not sure exactly what fish you're talking about, as there is some overlap in those common names. Are you referring to Colisa lalia? Those guys can be pretty territorial, I wouldn't put more than two in a 30T or maybe 3 in a 20-30 long. On the other hand, they'll be perfectly fine with a wide variety of bottom dwellers and even some quick mid-level fish.
I'd recommend a floating plant like duckweed or water lettuce for them to hide in, it will break up the line of sight to keep them from fighting, and they love to hide in it. IMHO live plants are always better, as they are good for water quality, but the gourami won't really care one way or the other, as long as they have places to hide. They won't mess with the plants at all, nor will they dig in the substrate, they are surface dwellers.
Dwarf gourami (including the different color morphs) are pretty heavily bred with hormones in asia, so they are known to be a lot less hardy than they used to be. I'm not sure what the lifespan would be, but I'd recommend buying from a local breeder if possible, or maybe getting a less popular species.
Best of luck, gourami are very fun fish, and can be quite hardy and easy to care for. I think you'll find them much simpler than your African cichlids. Feel free to keep asking questions!