Going with rack based servers will require more cables, transceivers and power, especially as you start to grow the solution. Each server will have to be wired and setup on a one-to-one basis, and as you grow you will repeat this process over and over.
Most co-locations charge on certain power bands, so the more servers you can get inside of the chosen power band the better return on your investment. This is where choosing a blade system will benefit you in the long run. You will only need to wire up the enclosure once, and adding additional blades will involve minimal interaction at the co-location. Most customers have the co-location “hands on” person just slide in the blade and configure it from the main office.
The choice now is which blade enclosure is right for you, the C3000 or the C7000. You’ll need to choose how you’ll manage this environment moving forward, as well as the SAS based solutions. For example, HP OneView is supported on the C7000. Have you looked at the storage blades? Do they provide enough capacity and minimize the need for SAS switches and external storage? Let us know if you have other requirements or questions so we can help you make the right choice!
And, yes, each blade would need to have a P741M to support SAS connectivity.