Designing an architecture for a process management system

You are an architect for a Fortune 1000 company that wants to create an internal task and process management system. The concept of the system is to give visibility to daily tasks that are performed throughout the company. Every employee is expected to use the system and be diligent about inputting tasks and to manage the statuses of the tasks as they move through the process. Your team was instructed to design an architecture that would support hundreds of simultaneous users. You have been given five physical servers and an old load balancer to run the system. You also have several licenses for SQL Server.

How would you provision these servers for maximum reliability, safety, and performance?
How would you manage the state in this situation?
If two servers shut down at the same time because of hardware issues, and the problem took several days to resolve, how would your application be affected?