Boot to USB

I have about 50 machines I need to image by the end of December. We are upgrading from Win95 to 2000. The Machines are HP Kayak XA’s and they don’t have CDROM’s. I can load the image from the network which takes about an hour and a half per machine.What I was wondering is….. Is there a way to boot from the USB port ether directly or by loading drivers on a floppy disk that point to the USB device??? I tried changing the boot device in the BIOS. I guess the next thing I’ll look at is updatingthe BIOS to see if that will allow me to boot to the USB device.
Thank you