I can't see the bow, but if it is a flat front jon boat, I wouldn't want to over power it - for my friends 12' jon boat 8hp is almost too much power. Based on the shape of the transom, I am guessing it is more like a v-hull - If it is a small v-hull a 25 will make it go well. I had a 25 on my old starcraft 16' (heavy hull) and it went right along in the mid/high 20's.
I've had super luck with the mud buddy blinds. Expensive, but effective and comfortable. You can rig up an almost endless variety of things that work as well or nearly so. All depends on whether you'd rather build or buy.
Also, I keep on reading posts about pop-up blinds (maybe flyway specialties?) here and they seem to have a loyal following. I've never used one like that though, so I can't say.
Charlie