tiger barbs can be very nippy when they're young. There aggression as far as I can see with mine is limited to their own species. They like to chase each other and like to determine a new pecking order each day. Therefore, they tend to stress other fish out, without actually hurting anyone.
Those cute little barbs in the lfs, get closer to 3 inches long and 2 inches tall. If you were to shave off the fins of my full grown angelfish and squish them down a little to make them fat, you'd have about the same body mass as a tiger barb. You really need a school to keep them from aggressing on others, so you'd need 6 of these. However, they need more space then a 3 inch fish, they need the space of a 5 inch fish for swimming room. I just don't see you or the fish being happy in a 29gal. If you were doing tiger barbs only with a couple of bottom feeders, you'd be fine
I hope this helps with your decision, you could, but you'd be better off not mixing them