I have 35 old drawknives so you can tell what my preference is. I get them from antique shops, usually for $15-25. I have skinny blades, thick, curved, straight, and 6" to 12". I personally find a straight, skinny 8" blade works well for me but it also has to do with the angle of the blade compared to the handles. Some people use them upside down, that is, bevel facing down. i think thats just them finding the angle that fits properly.
Just be sure the blade isn't pitted on the back, otheriwse you won't be able to put a good edge on it.