Personally... I guess it would be up to what you really want to keep...
If you were a more expierenced fish keeper I would suggest going with a peat moss filter media which will bring your PH down and IMHO give the water a really cool black water look from leaching tannins. Then you could keep pretty much anything you wanted.
The problem with this is that you might not like the black water look and you would have to an eye on your PH levels regularly. Besides that a stable PH is more healthy than the actual level.. But 8.6 is very high. Blood Parrots do best in a more neutral PH.
Here is a very informative web site that I use a lot. Look around.. Read for yourself...
Welcome to the hobby. I'm not an expert on Africans, so my advice to you is more general.
It is great to see a person new to the hobby post his water perameters and then ask about appropriate fish. This is so much better that another first post asking how many oscars can live in a ten gallon tank.
Your 29 gallon is plenty big. Just keep in mind that you can keep every kind of fish in which you are interested, you just don't have to keep them all right now or all at one time. Pick out two or three species from the suggestions given and then focus your energy on making as beautiful, healthy a tank as possible for those species. I always prefer to look at a habitat display rather than just a fish collection.
When you get an itch to try something else, then consider purchasing another tank or returning your tank's current inhabitants. This can be a good habit to get into and will help you to ignore the impulse to overstuff your tank.
I recommend returning the pleco asap. It isn't appropriate for your tank and will only be miserable in the long run.
OK. One fish suggestion: Altolamprologus Sumbu. A dwarf Altolamprologus which you could keep in the tank forever. Armkes has them available right now for shipping + $10. http://www.ohiexchange.com/armke/
Rainbowfish are beautiful looking. I've heard of some people keeping these fish with their Tangs. They prefer neutral to alkali waters and are carnivourous making them unsuitable tankmates for mbuna. I've heard of people keeping them as middle water or upper dwellers with their shelldwellers. They are schooling fish and prefer groups of at least five. They look outstanding in planted tanks. I think the glossolepis incisus ( red rainbowfish ) stays reasonably small and may be suitable for your 29 gallon tank.
Don't know too much about xenos. I think they are a schooling fish and would appreciate a longer tank. Tropheus are out of the question for your tank. They need to be kept in large groups ie. 10 or more and they need a tank that is 6 feet in length.
