Bio-load wise, in terms of what the tank can handle, I don't think you are overstocked. I do think you might have some compatibility issues which have been mentioned; Tiger barbs can be very nippy, especially to fish with long dangly fins like the gouramis. the dominant RT shark may bully the other one. Same with the acaras; if not a pair the dominant one will probably pick on subdom one, with cichlids unless you have a compatible pair usually 2 is not a good number.
