To your modified question in answer three, YES, it would be far simpler for you to change the IDE drive with another IDE drive and GHOST the image over to the new drive. I would suggest that you also run scandisk and defrag before running GHOST. You can GHOST this with the new drive slaved in and then GHOST the Master drive to the Slave drive. Once this is complete, remove the old drive and set the new drive as the Master drive. This would completely eliminate the installation of the SCSI controller drivers and editing the boot.ini. Should you decide that SCSI is the way to go, install the SCSI controller card first and install the drivers while still booting on the old drive. You should then be able to GHOST old to new, remove the old, set the BIOS to boot to the SCSI drive and edit the boot.ini file for the SCSI controller and drive. .... Simply put, sticking with IDE would be much more simplistic. Also be prepared to do a repair load of the OS, in either case. As usual, always prepare for the unexpected and backup your old drive first. I have also found it worth while to FDISK the new drive on another computer, without any other hard drives attached, and set the partition as Active when it is FDISKed.
I hope this helps.