Releated: not typical Magento reports

First of all you have think about next questions:

CPU Metrics

• Number of page views per day (peak/avg)
• Number of orders per day (peak/avg)
• Number of unique visits per day (peak/avg)
• Number of concurrent sessions

DB Metrics

• Catalog size (number of SKUs in catalog)
• Type of products (simple/configurable)
• Number of websites, stores and store views
• Number of categories

Security

• Number of concurrent admin users (i.e., users in the backend Magento)

Scalability

• Expected growth for next year/two years

• Average and Peak visitors per day
• Average and Peak orders per day
• Average and Peak unique visits per day

Hosting & Development

• How is the current solution setup? Servers and their configurations
• What are the site speed requirements? 
• Pain points or bottlenecks with current Provider