Try going to CVA's web site,and search for local dealers.
I just checked and all they list is a youth hunter, it doesn't say moutain stalker though.
A shop near me has a Traditions youth model in .45,sidelock.
I started my 9yr old this year with a Traditions St.Louis hawkin in .50.
He can handle the .50 with light loads well enough although it's a mite heavy.I would have gotten the youth model but my search was complicated by trying to find a lefty.
I did cut the stock to add a cushined pad and shorter draw.
He just shoots at the range off a bench so the weight isn't that big a deal now,he'll grow into it.