The one in the vid is interesting. The other one seems like it'd be super heavy. That's a lot of steel in there.
I'm going to try a quicky hand based off of the info i have. I'll shoot some picture as I go. The basic system is polypropelyne(sp?) tube. This forms both the 'bones' and the joints. The tube is cut to almost the length of ther hand and finger. At each joint a half circle chunk is removed from the tube about 1/3 the way through on the side you want the finder to bend. Cleaner the better I understand. I'm figuring on using a dremel with the little drum sander bit. Fishing line it run up inside the tube an secured to the tip of the finger.