If no luck on ebay, I got a replacement from NAPA. They had to special order it but it was nearly identical to the factory one. I think it was around $120 though. Because the mounting screws for the fan were so rusted in place, I ended up simply swapping the motor from the new fan to the old housing (still attached to the car). I didn't want to get into drilling and cutting so close to the fragile evaporator.
You could also give Hawk or Trail Tough a call because they part out trucks. Maybe they have a good one.