to the OP, some plants are more tasty to cichlids. As a general rule of thumb, anubias, swords, crypts and lotus plants that are a bit bigger and have a harder/crisper leaf are less likely to get eaten IME. Stem plants as well as young tender plants will be demolished by some fish including cichlids. I think most of the dwarf south American cichlids do well with most plants and wont bother them.
In my 75 I have 5 festivum, 6 laetacara and one angel. then I have a small school of corydoras and a small school of neon tetras. I would guess around a 1 to 1 ratio, but that's just my tank. My mixed cichlid tank is probably overcrowded if you went by the books, but I run a UV sterilizer, do large water changes and have lots of different places for fish to territorialize and it works well for me.
I will agree with what Grah the Great said about potting the plants, this helps to move them and suck up the poo when doing water changes. I also like to use sand so the waste sits on top and I can siphon it right off because cichlids are big waste creators. Don't get me wrong, probably all my plants have a leaf or two with a bite taken out of them because the fish have to at least try it once, but it doesn't bother me really. I have a thread on the tank on TPT its titled "My attempt at an Amozian biotope" I think.