Like these?
I think you are correct; the Hunter 'wellies' with high heels are seemingly discontinued. But be aware that Hunter boots now all seem to be made in China and quality may be variable, whilst the price tends to be very high. (Alas, Hunter also discontinued making rubber thigh waders several years ago - much missed and no readily-available (and affordable) substitutes.)
This range from Sweden may interest you, but again expensive: https://acquoofsweden.com/shop/