Noob as f@*k

[Vroomfondle]

Hi there,
I'm finishing a 73 super that someone got bored with and I found this site with all your killer looking rides. She's completely stock just now but the plan is a T4 in the back (my girlfiend has one in the garage ) with Boxter wheels. I got 40mm lower springs for the front to go on stock struts, but from what I read here they won't be much use. If I use the boxters will I need narrow struts? The wheels are 17x7.5 et55. Also can I get away with stock brakes until such time as I can get Porsche stoppers?
Thanks in advance for any help you can give.
ps
Here's an Idea of what I'm aspiring to