They are both really nice looking ponies. I would guess Shetland, no?
I like the paint better. The Paint seems to have better front legs. since they aren't squared up at all , it's hard to say, but other than the silver being a tiny bit back at the knee, I see no glaring faults.
I don't know if you are too heavy for them. I am also 5' 4" and I WISH I was only 120 pounds!
Good luck! they are nice ponies and should make someone a great mount.