the guillotines come in either 2" or 4" cut and they are not meant to be used for body shots, only head/neck shots because they will not penetrate the body. Plus you have to use long uncut arrows to keep those extra long blades away from your sights.
Pick a quailty mech. head such as the jackhammers, hammerheads, or even the rage heads. I like the extra cut that these heads offer over most fixed heads, helps anchor that bird quicker!