From a catcher's dad: those back-pack bags are cool, son had a catcher design when he was smaller that fit all his equipment and the 2 bats. Now that he is a full size kid, his equipment probably would not fit, his school provides the big wilson roller bag for catchers.
I did see the Georgia College and State University team a couple weeks ago had the back-pack versions.
If it was me, I would just wait until the first practice and see what the majority of other kids had. I do think it is a cool look with the backpack and the bats sticking out though.