Yes, as the pictures show, I have a 5 port PK brake.
Just to be sure, you should check with Kirby at APS about the price of his brakes. He can fill you in on all of that.
I have never used a JP brake. The PK brakes just came out so I doubt that anyone has tested them against anything other than what I did in this test.
Given what Kirby said about his design criteria and the size of the brakes, I'd say that he would tell you to use the 3 port brake on a 7mm STW.