Test Environment

I was recently involved in a project where the client asked me, "What kind of Test Environment do you think would be ideal for our application?". Frankly, i was speechless for a few minutes and then responded saying, "It depends on how your customers access the application". I know i was not correct but apparently i was not confident about what the right answer was. He again said, when i mean environment, i want to know what kind of Test environment you need for testing. How many servers do you need, is there a need for staging, how many VM's do you need, what kind of infrastructure(hardware + software) you need to replicate customer issues etc. I was not able to confidently answer him and hence asked for some time to revert.

Being in this league(QA) for a while now, i never had the opportunity to setup test environments or rather i never tried to gain knowledge in setting up test environments. After this experience, i realized how important it is for a Senior QA person to help clients in such cases since they completely rely on our experience to help serve their customers better. Request readers to share your thoughts.