types of fish

the tank is 90 cm x 30cm x 30cm I have 10 cardinal tetras that we put in 5 days ago as a start  I just want hardy easy fish .Would a 1 opaline gourami be ok or could I put 2 or 3 in with them  I read there was a barb ( that looked like a tiger barb) but didn't nip fins (sorry can't remember the...