If you go to my website www.broadheadtests.com you will find what I have written on picking the right broadhead. It should be helpful to you. As for uping your KE numbers the only real way is to increase poundage, switch to a faster bow, or increase draw length. The Draw length is the worst way. Fit is much more important. Increasing draw weight is the cheapest and as long as you can handle it works the best. Just be careful about going to much at once and make sure your arrows are still spined properly. With 47 ft/lbs the only head I would even consider in a mechanical is the Rocket naildriver.