Final Cut Studio 2.

Although i only run 5.1 on mine as i down own enough licenses of FCS2 to bother putting it on there, and i do all my ingesting through P2CMS and only have final cut there as a back up.

One thing you should do is get apple to check out the Powerbook, i put mine through a lot of general work (digitizing dv stuff for another company i work for) before i took it out in the field, after 2 days of doing this i discovered there were issues with the machine booting.

I left mine with apple techs for 2 days and after paying the priority fee they did a lot of hardware tests on it which they eventually came to the conclusion that it was the HDD. glad i spent that money.

I think the P2 card/HDD/Laptop issue is a no brainer, Just buy what your Budget allows, and that looks like what you've done.
I began with 4 x 8gigs when that's all that was available, I by-passed the 16's and waited for the 32's now I have Two 32's and Four 8 gigs.
I shoot mainly DVCPro50 PAL, SD. that's over 3 hours of card space, and 6hrs of DVCPro25, Everyone's situation differs so, choice of gear, use, and client demands all must and should be taken into account.
Great part about P2 cards is the weight factor, that's why I retired my V-Lock HDD from the cameras rear. But it does come in handy for some of those long boring "on the Sticks" events.
Cheers
Tom K