Is Ethernet on a Mac Mini = Ethernet on a G4 Tower?

As I'm sure most of you know, Mac OS X is not machine specific. With the exception of the PPC/X86 'thing', one version of OS X can boot any supported Macintosh. This little feature makes working on macs, and especially fixing them, much easier! So, more to the point. I have a Dual 800 G4 tower collocated at a data center. It is running 10.3.9 Server. I want to upgrade it to 10.4 Server but I have no physical access to the machine. The solution is to hook up a hard drive to this G4 mac Mini. Configure the mini as if it was my server, then ship the hard drive to the data center and have them install it. Then, just copy over all the data from my newest backup, to the 'new machine'. However heres the problem. I have specific IP and DNS settings I need to set on the server. If I set up the built in ethernet on a mac mini to connect to the network a certain way... then if I take that hard drive and boot my G4 tower off of it, is it going to see the built in ethernet of the G4 as the SAME network interface? Or is it going to disable the built-in ethernet of the mini, and see the ethernet on the tower as something new and just default it to DHCP? As you can see, this little question is going to make all the difference in the world. If it's the same, I'll be able to upgrade my server with barely a hiccup in service. If its not the same, then this plan won't work at all, and I'll have to have a week or more of downtime as they take my server offline, and ship it to me, just so i can put in the new drives, reconfigure the network settings, then ship it back out to them.