First step, sell the low mileage car and buy something with a blown engine or higher mileage. You're going to be rebuilding so much of it that it that you can probably make a couple thousand on the deal easily.
Second step, look into heat management for a turbo build like that, make sure it works with any aero you have planned.
The CD009 kit doesn't require extensive modifications to the tunnel, remove old brackets and weld on new ones:
https://www.mazworx.com/Docs/60150-F...dapter-Kit.pdf