Frostbite,
Win 98 SE was definitely distributed on bootable CDs - easiest thing is to put your CD in the drive, power off then boot up, check the BIOS is set to boot off CD, and see what happens.
You can then simply exit the setup without changing anything.
Of course, if the PC is SO old that it can't boot from the CD, then you have no choice to do as you say with a boot floppy.
You will definitely need Config.sys and Autoexec.bat to load the CD drivers, and it's well worth installing the correct keyboard driver and setting appropriate environment variables.
io.sys, msdos.sys and command.com are automatically installed when you make a bootable floppy.
SD