If you get tiger barbs you are quite restricted as to what you can keep with them. Unless you have 12+, they can be very nippy. I wouldn't risk gouramis of any description with them.
There are two terms that get mixed up, shoaling and schooling.
Shoaling means any species that needs to live in a group of it's own kind.
Schooling is a group of fish of the same species that like to swim round in tight formation.
Shoaling fish need to be in groups as they have evolved that way. If there aren't enough of them, their instincts tell them that something has eaten the rest of the shoal so they need to be on constant look out for the predator. This stresses the fish and can lead to abnormal behaviour, sickness and death.
Schooling is a defence mechanism of shoaling fish. They do it to confuse the predator. If they feel safe, very few species will school in an aquarium. The vast majority of shoaling fish don't school in our tanks, they swim all over the place separately. They only come together as a group when they feel frightened eg the first few times you clean the tank. Then they get used to that and carry on as normal - separately.
There area few species that are said to school more readily than most, and I've seen rummy noses on that list. I once had some serpae tetras for a few days. They swam round the tank in tight V formation. I only had them a few days as by then every other fish in the tank had bits missing. I now know they are notorious fin nippers, rivalling tiger barbs for that.
When you ask if there are any species other than tiger barbs that shoal, do you mean school, ie swimming round as a group? Because as far as I'm aware, tigers don't school unless terrified.
There is a more mild mannered substitute for tigers - the similar looking five band or pentazona barb. That is in the profiles on here but for some reason it appears to be missing from Seriously Fish.
But tiger barbs are on SF
it is relatively boisterous and does not make an ideal companion for timid, slow-moving, or long-finned species such as many livebearers, cichlids, and anabantoids.
Gouramis of all species are timid, slow moving and long finned.