Well the main reason I ask for suggestions is because I am not familiar with all types of fish, or their temperaments, needs, etc. I haven't been keeping fish that long so I am only fairly familiar with the small amount I've kept & I like to learn about others and experiences with them.. I'm not terribly picky lol. Just very open and curious.
The problem with getting the male to female ratio right is that I'm pretty sure I'd have to order online, as the only LFS in my area doesn't offer them.. Doesn't offer many fish, to be honest. Much less healthy fish lol. So I stray away from them as much as possible. And I don't know if ordering online allows for sex preferences. Would I just have to hope for the best? I think I'd definitely go with the gouramis over the Congo. Though I like them, I would rather have something a little larger that offers a little difference in visual looks than the congos.
I've never ordered fish online, so can't offer much advice on what a supplier may or may not do for you. If you have a good and reliable fish store relatively near to you, even if say an hour or two drive away, it may be worth getting to know them. Some stores will order in fish. I won't even walk through the doors of chain stores when it comes to fish, I have had no end of disease problems. I've never had this with the reliable stores.