OWC Slim ExpressCard/34 to eSATA Adapter... (EXP34SATA2F1) at OWC
eshop.macsales.com/item/Other%20World%20Computing/EXP34SATA2F1
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
This OWC eSATA adapter seems to be a winner. No drivers. Bootable. 64-bit happy. Paired with Lacie 4Big should be good.