I wouldn't recommend discus in a 29, they need a 55 gallon minimum IMO, and are a tricky fish to maintain as they require specific water conditions - low ph and hardness, with plenty of water changes. Angelfish would be about the biggest cichlid I would put in there, and I would get a second opinion on how many angels. I highly recommend a south american dwarf species though, they're lot's of fun. Mikrogeophagus ramirezi (blue ram) or any Apistogramma species. Or you could have a pair of convict cichlids, but you wouldn't be able to put anything else in there. Other suitable cichlids off the top of my head are africans like Julidochromis species and shelldwellers, but you'll need to do some water buffering to raise the ph and hardness.
(edit) almost forgot kribensis =P