I've never seen a frog buckle before. Good luck with that.
I do have one of the Equus sterling silver buckles and it's very nice. It's a substantial buckle and I really like the colour of the metal (I got the satin finish, which is matte). I'm not sure if I'd get a second one (IIRC, it's about 100 GBP more expensive than stainless steel) but I'm glad I have it.