Demasoni you need to make sure you get at least 12 of them they do best in larger groups, and you may have a problem when your giraffes get big that they may be able to fit them in their mouths. I don't know if it would happen because Dems are pretty quick but its just something I had to consider for my tank and I moved my dems out.
Johannii are cool, a little bit harder to get real ones with all the blue melo's and other randoms floating around, if you don't want to breed from them then these randoms are still cool fish which you will enjoy.
bumblebee's aren't all that colourful, males go jet black and females stay brown with black barring should be easy enough to get some of them.
As for adding fish and them getting along peacefully you are getting into africans so who knows what will happen, they are aggressive and terriotorial. Best bet is to add more fish the same size as yours and let them grow up together and sort themselves out as they grow.
Also don't add more than one species of peacock with brown females (unless you're doing male only) as you wont be able to tell what is what if you wanted to get them out again.
There are some pics of my 5ft african that took me a few years to stock here I have bred or am attempting to breed from most of them..
http://s47.photobucket.com/albums/f183/ryanjury/