Must the drivers for Recovery Console be provided via a floppy diskette, or can I provide them via a USB drive?
You will need a Windows XP CD or ISO. You can integrate drivers using nLite. Then you have to make have nLite make a new ISO file.
Then use Unetbootin to transfer the ISO to make a bootable USB stick with your new drivers pre-integrated.
There is a manual way but it is very time consuming compare to nLite.
Yes, they must. If the machine lacks an inbuilt floppy drive, there are USB versions available, which if I recall correctly will work for this purpose.