I also have a 29 gallon tank, Its easy to mix alot of corals, But you need to do alot of research. Some of your LPS have long sweepers that can reach most of the way around the tank. As long as you have your powerheads adjusted you vcan keep them together. I currently have, Frogspawn, Torch,Zenia,Candycane,Zoos,Shrooms,Rics,Fungia, and One XL Large Galaxia.
The only one I had trouble out of was the Galaxia, But I adjusted the flow so that he couldn't reach out and touch anyone else.
Here are a couple of pics of how the tank is done.