Planning is everything

Creating a new Moodle installation doesn't just involve configuring servers and installing software. That's just a very small part of the process. The most important part of the process is planning. Before you can plan, you have to understand the environment (that is, the people and the organization) that you are planning for. It is best to design your new server architecture in baby steps:

1. Audit the current environment, that is, your whole organization: How is your network configured? How will the new Moodle be accessed? How will the new Moodle interface with legacy systems? Will Moodle work at all?
2. Produce an options analysis: Designing a new architecture is a problem, not a puzzle (puzzles only have certain solutions whereas problems can have many solutions, some more effective than others). Each potential solution will have benefits and risks; these need to be understood.
3. Recommend a solution: The preceding two steps will make it clear why you have reached your particular recommendation.

Only when you reach an informed decision on which architecture you will implement, should you go ahead and implement it.

Obviously, how rigorous you need to be during the planning stage will depend on the organization you are planning for, still preparation is everything.