Hi Eric,
First welcome to the forum. If you are planning on breeding and raising discus I am going to suggest you start out with a group of six (small discus do better in groups) and raise them out. Raising discus is a bit harder then keeping adults and this is the best way for you to learn. While you have kept discus before I will still suggest you review the stickies in both the beginner section and breeding section. There is always new stuff to learn.
I will let the folks who breed discus go into the number of tanks for raising discus and sizes. My personal preferences are 40 for a pair and raising discus until they are 3 inches or so and then 75 to adult. I have only raised a few groups young discus some which I breed myself (all wilds).
Once you have successfully raise your first group of discus (note I said successful ) you might decide breeding is not for you. But try and then decide.
Pat
back later