I have a biocube 14 with live rock, mushrooms, ricordia, pulsing zenia, green star polyps, yellow polyps, zoos, macro algaes, snails and a few little gobies. I have left the set-up as supplied with no modifications and just do water changes. It is awesome and a lot lower maintenance than my wifes 180g with all her specialty corals. So I would say a 29g would even be better for a starting point. Just do your research before sticking things in.
www.nanoreef.com has some helpful tips for setting up such tanks.
Chris