The one I have is from Ameribag.
(I have too few posts to do links, just go to Ameribag dot com slash catalog slash product slash 32 )
The red one. It's huge.
I'm pretty sure the LL Bean ones are made by the same company, but they are smaller then the baby bag.
I have no doubt that the bag would be enough for everything you and half a small country needs.
If you do a store finder at Ameribag maybe you can find somewhere near you so you can try one of the bags on, and see how it sits on you.
I do like them better than regular backpacks. I think they are easier to put on and take off, spread the weight better and don't move when you bend down nearly as much.