The stock below definitely works, although it has to be modified. I don't remember exactly what the modification was, since I had a gunsmith do my son's, yet I'm almost certain it involved slightly shaving the part of the stock right where it fits into the receiver.
I found the above from a post by another member (I can't recall who) on here. I think I took a screenshot of the post and don't mind PM'ing it to you along with a picture of my son's gun, if you'd like to see how it fits. He killed his first turkey with it last spring, and we've had zero issues arise to date. A few of my friends did the same setup for their kids and have likewise not had any problems with it.
I could not find anywhere online where the stock is sold by itself, so unfortunately, you have to buy both it and the for-end, since they come in a set. Honestly, though, getting the LOP down to 10 ¾" for my son was worth it.
https://www.atioutdoors.com/product/shotforce-hr-nef-stock/
