... all FKM rubber straps available on a budget today are excellent. You can buy a no-name strap for less than 20USD on Amazon and have amazing quality, softness and comfort. This one for example is very good IMHO: https://www.amazon.it/dp/B0BV6YY1DJ
but Jean Rousseau has a bespoke strap site where you can create your own custom rubber strap or buy ready made of course, there is RubberB, also saw some colored tropic straps in Atelier Romane if you want tropic straps.