2.3 duratec on throttlebodies 200bhp and 200lb/ft

More torque than the S2000 and you could probably buy it (brnad new crate engine) and the TBs/Management for not much more than the S2000 lump.

Plus its going to be easier to fit as i'm pretty sure there are kits to fit it into mk2s?

The S2000 engine is a great engine engineering wise, but personally i hate the torque less wonder that is a rev happy vtec engine.