Just buys from Bosch, stamps a part number on them, puts them in a box and marks them up. Then the dealer marks them up.
So it only makes sense to use the same part Porsche uses where you can find the exact match.
And if you want the least amount of hassle, you buy the Bosch version with the pigtail already attached. That way there is little risk and the change out takes 20 minutes, 5 once the car is in the air.
What I've been able to find
And yes I used Bosch...no problems.