Back when I swapped my FAST stand alone O2 setup for a Racepak unit, i'm pretty sure both used the same connectors, although I don't remember plugging each in to see.
Here's the O2 sensor...
http://www.lsxtune.com/shop/product_...roducts_id/534
Here's it's mating connector...
http://www.lsxtune.com/shop/product_...roducts_id/678
The whole mating pigtail...
http://www.lsxtune.com/shop/product_...roducts_id/695
Grant