Answers to a few questions.
The instruction manual has all the info you need regarding extensions, ESC, motor, etc. If you elect to go with the Power 25 and never plan on using the Power 32, our 40 Amp switch mode ESC will do the job; EFLA1040. We list the 60 Amp because we believe over time someone might want to try the float flying thing and won't want to buy an extra ESC.
I would order it now to ensure you hit the first shipment. It seems to be hotter than I ever thought. We have ordered well on this one based on the response to the AT-6, but jump soon to garantee your bird.
The plane comes out a bit nose heavy when set up on floats with a 4S 3300 and the Power 32. The CG is right on with the Power 25 and a 3200 battery up front. The battery box extends into the cowling area to ensure the CG gets where it needs to be.
Don't know about any other motor/ESC configurations, but if you end up needing any weight in the nose, it should be a small amount. I never needed any on the final samples. The original did, that is why the battery box is designed the way it is.
I personaly was not a big fan of the DHC-2, but I will say this one has grown on me. I am coming to like the looks more and more every day.
Did I not say that things would only get better.