To be honest I just use the Apple Wired Keyboard with numeric keypad, and am pretty happy. Has a USB port for mouse. Should be able to get 2nd hand on eBay for a reasonable price.
I think Matias also make a clone of the Apple Wired Keyboard from 2007 as well - the official Apple ones are becoming hard to find I believe as they were discontinued around 2015 (though interestingly my college seems to get new ones with their new iMacs every year so YMMV)