-You really want a Mac, not a PC clone, for what you wanna do.
-You don't need a capture card--if you get a Mac, you just plug the
DV camera into the computer (via Firewire) and you can load footage...
It's very simple. You don't need to know about Pinnacle cards, etc.
-Any level of new Macintosh computer (including laptops) and a cheap
DV camera (one-chip) will let you get started w/ what you wanna do.
-yes, you can combine 1-chip and 3-chip footage, no problem.
In terms of Final Cut Pro... you should look at a newer product
called Final Cut Express instead... it's way cheaper than FCP, and
omits all the crap you won't need anyway.