I'd get in contact with whoever you bought the lock up assembly from, they should have their own. If you just bolt that assembly on, when the arms swing out to and press against the pressure plate, they will wear groves or possibly crack the pressure plate if you use a stock one.
Honestly if you haven't bought one yet I wouldn't suggest the one you posted if you can't get a pressure plate make for that lock up assembly.
If you would like, give me a call at the shop today and I can give you a price on an rpm 2 stage lock up.