If you want something that will breed like rabbits hit up some pink convict cichlids you will have 200 new ones every month. (female = red/yellow belly) as far as a lid goes I wouldnt use fiberglass for it doesnt let enough light threw most glass places are pretty reasonable for the glass you need to make a lid. However if you want them to polish the edges it will cost more but they wont be as sharp. I just bought some plastic that fit over mine. If you go glass you can set the shop light right on it or you can hang it in your canopy.
As far as fish go i would avoid walmart at all cost. Get to know the workers at your lfs just stop in to see what they have and talk fish. alot of times it results in great knowlege and even better deals. Also i have found that if you have them special order fish and can pick them up when they come in its cheaper then getting what they have in the tank. you might like a fire eel or some knife fish they are all really cool to see swimming around. Lastly if you are up for the challenge look into live plants. there are lots of youtube vids for do-it-yourself c02 systems. if you go this route start with the plants and give them a chance to start growing before you add fish as Africans like there plants.