This is a problem I had for a while, but when you install Slack and want to use the 2.4.5 kernel as and after setup, do as you said, type bare245.i and during setup when you get to the menu where it asks you for 'full' 'menu' 'expert' install, choose menu or expert, then you can choose the packages you do and don't want, including the kernel it installs. It should be in the very first menu. Choose 2.4.5 with no SCSI and you'll be groovy.
As for reiser i don't think it's worth it now that ext3 is around. It's also a journalised file system.