With your current lighting you'll only be able to grow java ferns and anubias, which should be ok with the Africans. They have a bad taste to fish, but some fish eat them anyways...go figure! If you upgraded your lighting to around 80 watts or more, you could add some vallisneria, which also is supposed to have a bad taste. Alot of people have luck with that.
Yellow labs should work. I'd get atleast 4, 1 male and 3 females. If you want more than that you should up the number of females.
I'm going to be setting up a 55g Mbuna tank in a few weeks and plan to have some java fern, anubias, and vals in the tank....we'll see how they do though.