Hi Alex,
What are the dimensions of your tank? It is maybe a little small for the fish you plan, escpecially if you are new to Discus keeping.
Your comment of waiting for 3 weeks for the chemicals to balance out makes me wonder if you understand cycling? There must be a source of ammonia for the tank to cycle, and it could take longer than 3 weeks. You do not want to be adding Discus to a tank that has just cycled if you can help it.
If you are new to fish keeping then I don't think Discus are suitable. It can be done, but you'll need to very very careful and do lots of research.
Very young discus should be kept in large groups in a bare bottom tank for best results. I would encourage you to buy Discus that are around 3-4", they will much easier keep and will settle in better. It is very easy to stunt young Discus if they are not kept correctly.
What's the filtration and aeration? Discus require slow water movement. You also need to consider the water parameters. They require soft water that is on the soft side. You will need to test your tap water and see if it is suitable. It's likely you'll need to use RO water to soften it down. If so your better of buying an RO unit to produce your own water. For best results find a decent Discus supplier/breeder and match their water conditions.
I think 6 Rams is a bit much, unless you plan to produce a pair and remove the other fish. A pair of rams with the discus could work ok. I would keep a group of 6 cories as they like to be in groups. Also be careful about the plec, which one is it? In a tank your size I would maybe leave it out due to the waste they produce.
