D16 future turbo plans

Ok I have a d16 non v-tec civic and my friend had one that he turboed with some kit from ebay and he was running 6psi and it ran fine. I was going to do that but by a Garret kit or Greddy kit. I was going to run low boost and then build the motor and then try and run somewhere around 15psi. I also thought about buying a b16 or b18. would it be cheaper to buy a motor or turbo my car and build it.