I think if you embark on something that has the potential to become quite large, you should not overreach. Start with something that works for you, even if not all the details are implemented yet. More than likely you will find that you do not need everything you listed.
You will get very far with Scientific Linux as you already mentioned. Have you also looked into Rocks Cluster (
www.rocksclusters.org | Rocks Website), which has a lot of what you will need right out of the box.