Honestly why don't you get the stock either new or used.
Get them from the Rx7club site in the 3rd gen used/parts classified ~
Just post Link:
http://www.rx7club.com/forumdisplay.php?f=99
Or call Ray crowe at malloy mazda and he'll hook you up with a new set for the cheapest oem price. Ray is the shit.
1-888-533-3400 Ask for Ray crowe