How to select vendor?

[Sumedh Chalermkanjana]

I am planning to build a new data center.
I plan to use one turnkey vendor to build infrastructure and procure IT equipment.
Most of my vendors can do turnkey.

If one vendor is good at infrastructure and I select him, he will partner with other vendor to procure IT equipment. The design is bottom-up.

If one vendor is good at procuring IT equipment and I select him, he will partner with other vendor to build infrastructure. The design is top-down.

How to select vendor?
What kind of questions should I ask vendors to find the best match for me?

Thanks.

[dilip.patil1]

Dear Sumedh

Most this types of vendors tell us we do anything, but I suggest you please go and see vendors previous installations or projects.

[Sumedh Chalermkanjana]

Suppose I go to see previous installations of data center of each vendor. What should I compare in previous installations of data center of each vendor? Going to see the previous installations would give me only a short time period for visiting and I may not be allowed to take photos of them. I may gain little information from seeing previous installations.

Or should I bring 3rd party data center consultant when seeing previous installations to do detailed analysis?

Thanks.