Even given the availability of the inexpensive KB motors and cheap Ebay LiPos (I have a few of them too), gasoline is still a far cheaper way to go with this hull size range.

There is still the ESC to consider, and the ESC can't be a wimpy one for the kind of current the big KB motors will have to draw to push a 40" hull through chop. I'd recommend no less than the Turnigy 120 amp one, and that adds another $80 or so to the tab for going electric. Gasoline will give much better duration too, since it is only limited by fuel tank size.

Rick