Mens winter boots?

My dad just asked me to find him some fox hunting appropriate mens winter boots. He wears a 10.5 in ariat field boots.

These are the closest I’ve found, but I’ve never fox hunted and don’t know if they are appropriate since they aren’t leather. Any other suggestions?

http://www.mountainhorseusa.com/footwear/winter-boots/active-winter-rider
http://www.mountainhorseusa.com/footwear/winter-boots/ice-high-rider-tall-boot

I think it depends on the hunt club. EVERYONE at our club wears Mountain Horse or a similar winter riding boot after the Blessing of the Hounds. However, I’ve heard of clubs located in a more southern location where such boots are discouraged. Michigan hunts can be REALLY COLD (-16 last year was the coldest huntsman went out) and really wet and windy. But again, hunts in the south don’t face such conditions and may have a stronger dress code.

Foxglove