From reading up on it, personal preference. Besides a skew chisel pair, or a fishtail pair, or a double sided fishtail, the other option I saw was a couple notches ground into a wider chisel to make a fishtail with a wider body on it. Clearly any will work. The next question is what can you buy (or make) today? Does it work good enough to stop looking, or do you need one of everything to make up your mind? Fords and Chevies, I am sure strong arguments can be made for all.