i started with a 29g tank as well and found it to be a good size. I used a hang on filter, an aquaclear 50 for it and eventually bought a hang on skimmer, a remora. I grew some crazy corals and the setup worked really well.
Key with a small tank like that and no skimmer is water changes. You have to keep up on them to keep your parameters good.
If you go with a sump reef octopus comes highly recommended. My experience has not been so great with them but it must just be me cause everyone else loves em. LOL