Here's an idea... Setup WB on WinUAE, and use an IDE adapter to connect one of the Amiga HD's to the PC. You can then format and partition the drive through WinUAE on the PC, install WB and anything else you may want. Remove the drive from your PC, install it in your 1200 and start rockin'.
Kind of a pain, but it's the best option I can think of aside from buying WB on floppies or a Catweasel.