I presently have 3 pairs of pony boots. Reactor pony boots found here , though at present they are not making any I'm sure if they get enough enquiries they may consider starting again. Who knows.
The Reactor (or Kayser) boots in my opinion are by far the best I have come across, and go easily from a specky event to the wearing around the farm. However my Mistress also went and bought a normal pair of horse yard boots which she modified to fit over the Pony Boots. (see pic below).
The Punative Pony Boots I have found here are the Rancho and the knee high patent leather boots.
I find these boots not so good. espeically with the wooden hoof and you have the option of putitng on the metal shoes. These metal shoes are very slippery and i ended up removing mine.
A lot of people also find these boots very hard to walk in. But like ballet boot training you will have to train yourself to walk properly in these boots.