I use an US keyboard.
There are two reasons for that:
1- I learned typing on a QWERTY keyboard first (on terminals and TTYs in 1975);
2- but foremost, I noticed that most programming languages are designed in the US, or by people using a US keyboard, and use the special characters of the ASCII character set easily available on a US keyboard layout.
When you try to type programs on a different layout you will quickly notice that each special character needs more complex key combinations to be typed, which gives a much less fluid typing of programs.
For natural language text, it wouldn't make a lot of difference, since there is a much lower ratio of special character to alphabetic characters.
Now if your programming language was Qalb, then I would definitely advise to use an Arab layout: http://nas.sr/%D9%82%D9%84%D8%A8/
https://en.wikipedia.org/wiki/Qalb_(programming_language)
There's little difference between the US and UK keyboard, however, I much prefer the wide horizontal return and left shift keys of the US keyboard than the narrow vertical return key and the truncated left shift key of the UK (and other "international" keyboards). (Strangely enough I use almost exclusively the left shift key over the right one). So I would definitely advise to explicitely ask for a US qwerty keyboard, and not just a QWERTY keyboard because some vendor will then just deliver you an UK keyboard.
A final point: we use a lot of different computer hardware and systems; each hardware has its own human interface variants (keyboards, trackpads, mices, trackpoints), with different software keyboard layout and functions (notably regarding the modifiers and function keys). IME, this is where most of the pain comes! This can be solved by using the same keyboard and pointing device on all your computer systems. Happily, nowadays it's easy to do, thanks to USB and bluetooth: you can buy eg. half a dozen Filco Otaku Tenkeyless keyboads and half a dozen HP logitech 3-button optical mice, and thus have the exact same physical interface to all your computers. Remains then only to configure the software keyboard layout and modifiers keys identically on all you computer systems (easily done with Xmodmap on X11, harder to do on macOS and MS-Windows, but still possible. At least, if you use emacs (but as a programmer, I assume you DO use emacs), you can always remap all the keys and modifiers to be exactly the same everywhere, if only inside emacs).