Best polish for homemade Maxwell St sandwiches?

Who sells the best sausages for homemade Maxwell St style Polish sandwiches at home?

Seems like every little ma and pa grocer up to Bobaks sells a polish they label as Maxwell St. I tried the Bobaks and it was OK, but just not quite there.

Also I read something on another thread comparing Jim's Original and Express Grill about corn oil.. Is this poured on the sandwich directly or is it used in the onion grilling?