I've heard very good things about the Keychron keyboards[1], especially on a Mac (the design is almost Mac-first) - the K1[2] and K3[3] are both low-profile and should be as quiet as a mechanical keyboard gets with Red/brown switches and you can opt for optical switches too - also bluetooth so it's fairly portable. Although there's no firmware/software to remap keys so you'll need to do that on the OS side.
Companies like HAVIT[4] and Coolermaster[5] have made them too, but I haven't heard much about their stuff.
[1]: https://www.keychron.com/
[2]: https://www.keychron.com/products/keychron-k1-wireless-mecha...
[3]: https://www.keychron.com/products/keychron-k3-wireless-mecha...
[4]: https://www.amazon.com/Mechanical-Keyboard-Extra-Thin-Rollov...