273 or 225?

Probably a NA 2.0l has more power potential than a /6, at best you'll probably have the power of a modern peppy NA 4 cylinder. If that is ok build away. Do the six cause you want and odd ball peppy concept (dare to be different kind of thing even though more /6 A bodies were built) not cause you want power unless power adders are in your future.

/6 guy's are like 360/408 guy's they all think you should run what they do. Run what you want as long you know the compromise.
Maybe you should read my posts again.