Thanks for the replies!
Jeep: I'd like to keep the power on the low side. The kids are 12, and while I trust them they have little experience with things that shoot. They made hickory bows, but as we know that is a different animal than a crossbow.
Mine, however can be stronger muahahaha.
As for the stock, I have an offset on it, that I hope is deep enough. It is certainly enough for the sling to clear. It is 2 pieces one 1.5" the other .5" with an alternating grain to give some more strength. I'm not fond of using red oak, but I have a very limited budget.
As for the prods, I was going to temper them at 700F It is 1075 1/8" thick 3/4" wide and 28" long.
I'll play around with prods on the prototype before they make theirs, and find a good fit.