If you want to run multiple operating systems, look into http://www.microsoft.com/virtualpc or http://www.vmware.com/products/desktop/ws_features.html
Software emulation is MUCH easier than dual boot, and it's a hell of a lot more flexible.
Buffalo Technology makes a great set of bridges, routers and wireless cards. See http://www.buffalotech.com/products/wireless.php Most people don't know much about them because they don't have the shelf space you see for Linksys or D-link.
If you read through the details at bungie.net, you'll see they are locking down the exploits, cheats, etc. As far as the map pack is concerned, I hear ya. I wish the goods were free, too.
Most likely, whatever you have with Comcast will be just fine with Verizon FIOS.
However there are a few things to consider, especially if you want to plan for the future:
1.
I just wanted to see if what .s1 said was actually true. It isn't but that wasn't the point. Most of the games will not install on WS 2003. Doom 3 would not. The setup programs detect OS and block. You can get around those with the various compatibility modes or the Microsoft App Compatibility Toolkit. I didn't use either on Half Life 2.
I don't however recommend you do this. You'll find more hurdles than it's worth especially if you are using a server without an AGP slot. I'm using a beefy -1 gen laptop so I was pretty confident it would work for one of my games.
Stick with Windows XP. You'll be glad you did.