I've never had gouramis.
I bought 4 Ocellier catfish for detritus cleaning. They're tiny- I know they get large (I may have to adopt them out if they survive). I got them online, then QT'd them for a week. I introduced one to the girls' tank- I really haven't seen him (or her?) since. I have noticed that the girls are drawn to the back corner of the tank; to the point that one or two were obsessing about it. I was worried- then I saw a tail flip- the Ocellifer had been hiding under the gravel there and the girls are too curious.
I selected the Ocellifer cat b/c it's a bottom feeder that can handle a wide parameter of water conditions, and they don't get as big as a pleco (which is what I wanted. The smaller, pretty plecos cost $$$ if you can find them!).
I'm disappointed that they are shy. Can they injure my bettas? Or should I worry about my bettas killing him (and the others, still in QT- I wanted to see how 1 would work). I'm going to cross-post this on the 'Tankmates' thread.