I have zero knock lol, doesn't take a lot of money, it's all in tuning and matching parts accordingly. Also, seafoam smoking a whole lot doesn't mean it was dirty, seafoam itself smokes, have you check everything again after you seafoamed? it's possible to foul out plugs with that crap.
Not sure where you picked up that AEM dry flows don't flow as much as k&n, I use a Dry flow. It flows justas good if not better with the same if not better filtration. If you wanted maximum horsepower you could just run without a filter, we all know that isn't a good idea though. Pick what you think is best and what you like, this will be just like asking what oil is best for my car.