Hi Anchor Boy,
I just repowered (twice now) with the 4.2 liter. I have a collected 10 hours experience with it. I love the digital controls and it was worth it for me to go digital. Twins may or may not be worth it.
The 200 inline 4 has had great reviews. The question is the displacement greater or equal to the current 6 cylinders? You're going from s 2 stroke ,which often have better low end torque to a 4 stroke. The inline 4s may be great for that boat. The 4.2 225 would be awesome for it. If you can't go that route due to costs the Suzuki ain't a bad choice either. You could hang 2 G2s on it too.