Gorgeous snake! I'm a brit and I've fed live when necessary (hatchlings, desert spider on 13 month hunger strike lol) I've heard of people keeping a pencil handy incase the food has its head free (to give it something to bite) I've never had to intervene. You may be surprised at how efficiently constrictors kill. I always used to think there would be minutes of suffocating but it really is more like instant heart attack. It's not something I enjoy but sometimes you don't have a choice. It may be worth trying yours on a thawed frozen rat with the head heated above room temp first, you may be surprised. Could be that the pet shop just found it easier to stick with live either way good luck and again, congratulations on such a stunner!