I'm trying to build the kernel (with ToH patches), and I was wondering if the entire Xcode is required, or will the gcc 4.2 preview on apple's dev connection site be enough?

Eventually I plan to do some kernel hacking for better sse2 support (stop laughing), but I'm not sure whether I really need that humongous 1.1 GB download or not.

Also, any hints on where to find The Key ?