Log On Today - Fish On Tomorrow! ™
Lots of good info already posted here for you.
E-tec are very nice motors but I also would recommend a 4 banger for what you want to do. That's just my .02.
Get the 25 HP and you can slow it down with bags or a bucket as Mike suggested. My buddy ran a 16' Lund with 2 bags on the forward cleats about midship with great results. YMMV.
I just got a boat and run Yammis and am happy with them so far. I think the 4 stroke Merc's, Honda's & Suzuki's are all solid choices as well.