Adobe Premier 6.0 is the best I have ever played with... Especially if you have a DV camcorder as 6.0 is pretty much DV-centric. Simple, straightforward, intuitive, yet incredibly powerful.
Oh... and DO NOT use Ulead Media Studio. WORST EVER.
Oh Oh.... Firewire cards are pretty much all the same when it comes down to it. Just buy a 3 port card and you'll be fine. As far as I recall they all run off the same TI chipset so the meat and potatoes are the same.
Welcome to the world of digital editing... It's a blast but can make you want to tear your hair out too.
Be prepared to waste time and HD space (A LOT of HD space) =)