If you want Barbs, then I'd recommend Pentazona as they are a peaceful fish that doesn't grow too large.
I wouldn't put a shark in that size tank as they become very territorial and aggressive as they mature.
not looked in to what kind of barbs i want. i had 12 tetras which deid so i have to sort out my tank first. can you suggest any barbs that will go with the gourami or any other fish but not guppys,mollies or tetras