GOOD NEWS. . . . The PICTURE UPLOAD FUNCTION IS WORKING !!! The tech folks at the parent company have been able to remedy the issue. You can upload pictures once again. Thank you for your patience.
I also have a 14ft jon with a 15hp. I use two 8lb mushrooms. Holds good when the wind isn't two bad. On a river or when it is windy it won't hold and I start drifting slowly. I was thinking of buying a anchor with a hook feature to use when on a river or in strong winds. But there is just not any room for such a large anchor so I will probably stay with just the 2 small anchors.
A 10 pounder should be fine for your boat, but what's also important is where you use it. Mushrooms are fine for sandy or muddy bottoms, but if the bottom is rocky, a Danforth is much better.