I was looking for Meriah's too, but didn't want to swallow the $385 price tag, and I couldn't find a manufacturer for them online. Therefore, I concluded they come from another application and have been adapted to (or custom developed for) the Pantera. But, I did find Cool Cat fans. They cost a lot less than Meriah's, and they're popular with the Jaguar crowd:
http://coolcatcorp.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=CSI started looking into these but ended up rebuilding my original Lucas fan motors (new wiring, brushes, paint, etc). The Cook Cats look similar in size to the stock fan motors, but I didn't check actual dimensions. They also have a much more aggressive (effective) fan. Let us know what you find out, and if you go with these.
Cheers!
Garth
www.banzairunnerpantera.com