I take your bios settings are all correct.
If it's just for installation you could use a boot floppy to either boot the cd or do an ftp install.
As for the usb cdrom, you need an OS to acces it.
I geuss you could use one of those floppy distros, but this could be very complicated.
Once you have a working OS, you could use this howto to make the usb cdrom work.
(it worked for me)