New OS Installation

I have a 40 gig HD with WINXP. I would like to install a 60-80 gig HD and put my existing XP onto that HD with my programs,etc and then put 98SE on my existing 40 gig drive. How can I transfer my contents over to my new drive and then “wipe” my old drive clean. I have a PentIII with 512 MB. Will my BIOS recognize a 80 or 100 gig if I choose to buy it?