Any help would be appreciated.

I'm building up a 2004 KLEIN A ttitude frame and want to swap over parts from my 1998 TREK 6500 bike with Marzocchi Z2's from 2000. Here's a list of snafu's I have encountered before taking the bike apart.

Seat Post: need new, Klein is thicker
Front derailleur: may need bigger?
Bottom Bracket: as far as I can tell, they are the same?
Marzocchi's and headset: ?
Anything else?

Thanks