Engine size recommendation

Thanks to all for the time and input, this information is exactly what I needed to know. It sounds like I can accomplish this feat with either set-up. I think I will go with the 318 since 1) I already have one and 2) I like the idea of keeping the same size the car came stock with.

I haven't been a member of this forum long, but I'm very pleased with how active and helpful everyone has been.