I think the zuke 90 and the e-tec 90are the superior options in the weight/power arena.
I think bitsamonkey has a late model DF90A zuke and his numbers were impressive, albeit on an 18. IIRC he was getting 37 mph WOT and showed 6.7 mpg @ a 27mph cruise. Its about 25 lbs heavier the the e-tec 90, but the gear ratio is like 2.59 and allows for swingin' a burly blade.
That being said I think that e-tec 90 would be sweet too. The economy of the e-tecs at hull speed (no wake, trolling, etc.) is amazing. I have no idea on their respective torque curves.
I think either would be very close in power to older, lighter 115 hp 2-strokes.
If I went 115, I think the e-tec would be my only consideration. Bushwacker's 150 was freaky silent at speed. I presume the 115 abides. Dude
. That knocks the Optis an Tohatsus aside for me. The nominal extra weight of the Yammies, 4-s Mercs and Zukes is the dealbreaker for me. Now if I got a steal of a deal - I'd start moving stuff forward.