I would always recomend a G4 notbook if you are going to consider a laptop for editing but you'' still need software and soundcard.
As for a pC based system.
SOFTWARE: I am gonna recommend Vegas, not just because I use it but because it will suit your needs specifically. It's part of the sonic foundry audio family so it's routes lie in sound and it has all the audio capabilities installed. It will do what you want and more eg (live dubbing with a decent sound card. Make sure you get the Vegas + DVD Architect Bundle(so u can make your DVD's). Vegas is also very easy to learn and the interface is clean and clear.
As for Sound Cards - You'll need a USB soundcard with a breakout box. Something like Digidesigns Mbox
http://www.digidesign.com/products/mbox/
Am not too sure on the US price but this or something similar will do the job. It may not have as many connections as you are looking for but strictly speaking if you want more than 2 inputs you should get your self a small mixing desk then connect that to the sound card. You can probably pick up a desk on ebay cheaply and it's worth looking for one if you are going to be doing more sound work in future.
If you want to take tracks from CD's you can use any standard ripping software. Just make sure you rip the trachs as Aiff's or Wav's as these are as near to uncompressed when you select the highest settings . Vegas has it's own "improt from CD" function that brings tracks in at CD quality.
Hope that helps, ask again if you need more advice.