I understand your concerns. I was sorely disappointed too when I found out that my BEAUTIFUL Fuchs will not clear the fenders too....
And for your info, it's not just the rears, the fronts will not clear as well.
I figure it's a cost vs. performance issue at the end of the day. The stock 944 brakes will out-brake any other front/rear setup and the only additional money incurred will be for widened fenders. If you want to retain the look, you can go for 1" widened fenders. You cannot tell them apart from the stock ones.
Of if you want all-steel fenders, you can cut and add a 1" strip yourself.
I wish you success. And hey... If I need stuff machined, can I buzz ya?
Sprint.