If you are looking for a small office or home office setup, i'd go with Dell. They have a live help option where they can login to your setup, fix and troubleshoot any issues, and it's included for the first year depending on the package you pick up.
If you are looking to run a datacenter, hosting center, or large office.. I'd definitely go with IBM. The capabilities of the systems IBM have in place power a huge percentage of the large business market right now, and for good reason.
Since your's is small office chose the cheapest providers.
I can suggest you medhahosting.com, since they provide servers at the cheaper cost and they give the money back guarantee if you are not satisfied.They give 24/7 support