Wow, didn't know Baffin made so many kids' boots.
All the ones we had for the kids sucked when they were little (pull on Sorel type boots, not tall enough). I resorted to duct tape as well, wrap the bottom of the sno pants and then under the boot like taping up an ankle.
Older one,9, uses his snowboard boots now.
Younger one,6, has had a pair of Bogs for the 3rd? year now. Rubber bottoms, neoprene uppers.
I'd reccomend those. They're tall enough to go almost up to the knee so no snow gets inside and they don't pull off easily in the snow. No laces, easy to get on and off and his feet have never gotten cold in them with a pair of wool socks.