It isn't hard to find a great fitting pack for young kids (the Dueter Fox 30). For kids under 10 this is one of the best fitting packs around. Makes a great, excellent fitting daypack after they get to big for using it for backpacking.

This pack is NOT UL. Neither does it weigh 4 lbs though.

A well fitted pack does wonders for kids carrying a load, be it heavy or light.

As for shoes? LLBean. They sell excellent trail runners, boots, hikers, etc for kids. Same with rain gear, fleece, down jackets, pants, etc. They are not cheap, but you get what you pay for. Sierra Designs carries kids clothing as well. So does REI, Patagonia and my two cheapie favorites: Target and Walmart.

I can say that kids gear is out there, you just have to know where to look. Ford has pretty much always had a kids version of my gear since he was 4.