I did have a 29g at one time, it had about 30lbs of LR, a shallow layer of cc, 55 watts - PC's, livestock included mushroom corals, various feather dusters, a yellow sponge, astrea and turbo snails, 1 percula clown, 2 scissortail gobies, 2 firefish. It also contained 1 mantis shrimp (came in on a piece of LR). It was a nice set up but for the mantis and the cc. The mantis ate all the hermits I put in the tank, plus the scallop and the occasional snail. The cc was okay in the fact that it had a bunch of different critters in it, but it didn't look too great.
Even though the tank was overstocked, all the fish did great and so did the mushrooms.
This tank started out with a skimmer, but after awhile it was removed. So the equipment ended up being a HOB filter, 2 powerheads, and a heater.
One thing about a small tank, it's very important to do regular water changes!! It will help to keep things stable. Another thing, even though I was overstocked on the tank, it is important that you know that I have been keeping fish for a long time, and I feel I have the experience to deal with that issue.
When we moved, I decided to redo things, and the 29g was retired (for the moment).
HTH
Good luck!!