A 29 is a bit small - you can choose some of the small labidochromis species... take a look through those websites. Anything else (pseudotropheus, haps, aulonocara, etc). will outgrow a 29 eventually. the exception is the pseudotropheus lanisticola (otherwise known as maylandia livinstoni) is a shelldweller from lake malawi which remains under 3". there are other small (under 3"
africans but I don't know the names.
2 or 3 yellow labs, a few labidochromis jacobfribegi and a synodontus catfish would make a nice 29 gallon tank - perhaps a dwarf bristlenose instead - synos tend to get big (4"
.
Lots of rocks, a good powerfilter, and maybe some cichlid proof potted plants (small swords, vallisernia) would make a nice 29.
The most common method to reduce aggression with african cichlids is to either overstock the tank, or provide 1 male for every 4 females of each species... which is why I suggest a 29 is a little on the small side. but you COULD have 1 male from different species..... downside to 1M/4F is they breed quite readilly and you might need more tanks in the near future