You just need the bracket? That's part number 73610AC000. Under $20 at subarugenuineparts.com, plus their expensive shipping rates.
Probably not much more from Lithia.
Now that I think about it, I might even have one since I pulled the A/C off my 2002 WRX... but finding it will be a chore. No idea what box in my shed that would have ended up in.