You don't need part numbers, unless you want to pay a fortune to a stealership. I bought mine from a Toyota dealer on ebay. I just checked, there are at least three of them for sale on there now. Looks like it will run you about $235 delivered to your door.
Search "4runner roof rack" and you'll find them mixed in with the results. Some are listed as for the Urban Runner, but it's the same rack as the Sport Edition. They look grey in the pics, but they are black. They are brand new.
Good luck.