I have been scouring the innerwebs for offerings like this, but with a gaming last for weeks my friend and the pickings are slim.
I am typing this on my Logitech MX Keys (scissor type keys, not mechanical) full size and I have been in love with this keyboard from the first day I used it a year or so ago. I got it provided to me from work and I was just stunned by the typing experience.
Personally I have been looking for a small form factor TKL or smaller gaming oriented mechanical keyboard with clicky/tactile keys, AND the 2.4Ghz receiver.
You can probably avoid all the super custom keyboard madness and boutique suppliers for what your looking for because apparently none of them care for good wireless connectivity and they all rely on Bluetooth.
I assume you already had a look at the Logitech offering on their website. Try the other brands product websites for options, Microsoft, Dell, Lenovo for office orientated options.
But if you are looking for strictly mechanical you might as well get one from the gaming focused brands. Razer, Asus ROG, Logitech, Corsair all have wireless offerings with the radio connectivity.
I live in the Netherlands and when I want to see what the market has to offer for a particular product with a particular feature i use our local price aggregator, with powerful feature and specification filters.
Filter for 2.4GHz, or radio connectivity and go from there.