Welcome to WHT
In terms of server specifications, it is totally depending on how loaded or how many clients you have or expect to get. I believe a Quad Core processor and perhaps 4GB RAM has become the minimal standard when it comes to a shared hosting environment. You may see some providers offering Dual Quad Cores with more RAM but the amount of resources depends on how many clients you have or expect to put on a single server.
As for support, you can choose to have your own in-house team or outsource additional support. You may want to look at this section
of WHT for more information in regards to support and management.