This is a good question for the data centers you are thinking about using. All of them should have sales reps that will tailor the server to your needs, and let you know which version will be best for what you want to do.
For your shared hosting, I would recommend you to use 2008 Web/Standard.
If you're thinking of putting your VPS and Shared Hosting together, then I would say... get yourself a better server 1st.
Then again, if you're going to be putting 40VPS in 1 server, I don't really care which OS you use going to be using because 40VPS in 1 server will be something interesting to see, especially the server you mentioned.
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Thanks a lot. Would like to know if I would like to sell VPS (xen 512MB x 40, 15GB HD each), what is the minimum spec of my server?. Many thanks.
You'd need at least something with Dual Processors. I'd recommend Dual 5520 or higher. Raid 10 or higher is a must as well. You can get away with 7200RPM drives provided they are Enterprise grade drives (SAS or Western Digital RE4, or similar). I'd recommend Adaptec 5405Z RAID cards as they tend to have some of the highest throughput I've seen with Raid 10 on RE4 drives.
█ Matthew Rosenblatt, and I do lots of things.
█ Currently a Master Electrician on Broadway.
█ My company, BurstAV, specializes in A/V Systems Design and integration.
█ I also own ConcertCables. We build power/data cables for the entertainment industry.