What engine setup (blown small or aluminum big)

If you are questioning the economics of it now, I's suggest you re-think things. A 10 second Mopar is a lot more money than a 10 second Ford. A streetable low 11s car will run you around $17K give or take to build from what you have. That's for the safety stuff, the cage, a real transmission, suspension and tires, and engine. This is a realistic guess, not meant as a cut. But that's what it takes to do something reliable and safe.