Is your BF and member on here?? If so he might have posted a few times with his plans for the car. My fiance also did this for me for my graduation gift. She bought me my new motor for my suzuki samurai project!! I keep a journal with a detailed log of my plans and where I am in the builds, parts to source and from where ect. Since I always have multiple projects going at once. He may have something similar either on paper or in his computer.
The Corksport is a nice exhaust, but if he is planning big power real soon, it won't be enough for his build. The corksport is only 2.5 inches where vibrant and Perrin are 3 inches. You need to know what his plans are.