I use the Mister Twister and like it fine. Not sure on the length but it cleans a walleye with no problems. Also, try this link: Electric Fillet Knives Posts
I’ve tried most of the different makes and models out there and hands down the American Angler is the best unit. I am on my forth year with this one and I have yet to change blades or have the motor burn up in it. The biggest problem that we see as guides in this area is the motors burning up, its tough to clean a days catch with an electric knife that is always warm and on its way out. Some of the other brands heat up causing the breakers to trip at the power outlet…never with the American angler though. Well hope this helps….