I believe you can run that as a dual boot, although you may need to buy some third-party software to boot between the two. Keep in mind though, you cannot run both on the same machine at once, without buying yet another product that will run an operating system in a
"virtual machine" - most of the time, it's not worth the extra money, as it's nearly as cheap to simply build another machine to handle your needs... Not to mention that it will run better on seperate machines.
Networking Unix and Windows is possible with
Samba.
It will depend on your specific network setup whether or not you need a switch versus a simple hub, but Unix will allow you to do it either way. It's just a matter of configuration.
(Also, it is usually a practice to respond back to the message boards instead of direct e-mail you, so that not only can others benefit from the conversation, but somebody could correct or add on to what has been posted. That's why I'm posting, not e-mailing. At the bottom of your screen, when you post a message, you can turn on "Email notification", which will contact you every time someone posts a new reply to your question.)