I suggest a live CD type of distro. See www.distrowatch.com.
The reason for a live CD version is that the USB drives contain flash memory. While they have unlimited reads there is a limited amout times you can write to them. Granted its thousands of times but its possible. I did it with an EEPROM (similar to flash memory) with a firmware error.
You will either need to recompile the kernle to include all of the required USB modules or add the modules to the initrd. Not all PCs can boot from USB, so you might need a boot floppy disk.