Like you said you are getting a laptop and want to plug in all the things your PC typically had. If you are planing on getting the new aluminum macbook I would recommend a USB Hub (20 bucks at most places). I bought mine at the apple store and it works great, basically it gives me 5 ports instead of 2.
Depending on how you want it set up, I have the new macbook but most of the time is is set up basically as a desktop. I have it closed with 2 monitors, wireless keyboard, and wireless mouse.
Like you said, you have 2 monitors, you have 2 options here.
1) Use the laptop's screen as 1 monitor and only 1 of your other monitors as the other screen. Personally I dont like this but there are a lot of people who dont mind.
2) Have your laptop closed and use 2 monitors.
Regaurdless of what option you want you are going to need this:
Mini-DVI to DVI adapter
http://store.apple.com/ca/product/M9...mco=MjE0ODQzNg
or
Mini-DVI to VGA adapter
http://store.apple.com/ca/product/M9...mco=MjE0ODQzNQ
If you want to have it set up the way I do with 2 external monitors you are going to need this:
http://www.matrox.com/graphics/en/products/gxm/dh2go/
It works pretty well, it basically takes both your external monitors and makes 1 big monitor out of it. The downside to using this with a mac is when you expand a window it will go over 2 windows and not snap like it does in windows.