A quality street port and polish with valve job will run between 800-1000. Like I said, with a type R head do the internals of the head and a good cam first. Depending on the mileage of the motor and any damage that might be there a good valve job from someone like DFE would be a good idea. In an all motor build like you are talking about you would benefit more from the valve job than you would with the port and polish. The valve job is the key, that's why people like DFE who have tested different valve angle cuts to see which one is the best keep their angles a secret.