Rob, I don't think you will get much from a cam swap right now. I would wait till you get some heads then get it all at once.
The Nitrous Express kit is nice, are you looking at the wet or dry sysytem? I personally am going to a Top Gun N2O kit, they are the only company that makes a plate kit for my Holley.
http://www.moxieracing.com/index.htm...itrous%20Oxide