What size tank are we talking Lady G ? That pretty much determines a lot.
In respect of haplochromis, that is a very large group of species, varying quite a bit in size and attitude, also in tank mate preferences. Generally, malawi haps however are the larger guys who predate on smaller fish.
The lab. caereulus is most often the yellow colour morph (blue and white also exist) and are little stunners - great choice for any mbuna tank.
Cynotilapia most often means Cyno Afra - another beaut, usually people have access to a blue variant, although over here lions cove are available frequently - nice little black and yellow stripe.
Pseudotropheus - usually zebras, or many colour morphs available, also could mean acei/socolofi Any preferences/what is available locally ? A pic/description would help.
Labeotropheus most often means trewavasae/fuelleborni - nice fish - a pic or description of what your thinking of would help - fair few colour morphs here too.
Everything you're looking at except the haps are mbuna which should be stocked in harems, ratio of 1 male to 3 or so females (minimum 2 no maximum). Same goes for most malawi haps (in fact I think all of them). If the tank is truly big, a nice way to stock them is some groups of mbuna and then a few male haps of different species (the females tend to be a lot less colourful).
Regarding a black water look, I actually think the fish are best presented with pale substrate, pale rockwork, black background and crystal clear water. In any event, you want your Ph over 7 minimum and 7.8 to 8 would be great. I think that that being so your problem in creating blackwater planted would be keeping the plants alive but I'm no planty. Regarding keeping them at Ph below 7 and getting a lot of tannins in there, I don't know how successful that would be.
Plantwise, plenty of choices. Anubias, Valls, Java Fern, Java Moss, Crinium (Onion plant) will all do fine. The trick imo is to plant mucho green stuff, so that even though they chow down on it, some will be recovering while the rest flourishes.
ps. I'm a gonna stick this over to the cichlid forum if that's ok
