I have setup several test labs using their own IP ranges, off our network. I'm working on getting a good server in place for my home, before I put up a domain.
As to the IP stuff, I always setup DHCP. I hate static Ip's cause then it's a mess if you have to change anything. Also, DHCP allows you to make the reservation to a mac address, so it's always the same anyway, but the software controls it, so you can change it from anywhere, with the right permissions.
If you want to setup a special IP for it, either have 2 nics, or a router to control access to it. You need a route for the machine to find it's self.