Since I'm from Europe, X-keys would be extremely expensive to ship over. Is there any good alternatives around (preferably available in europe?)

I used to have a G15, which had the extra 12 (?) keys which I programmed for boxing, but I have a mechanical keyboard without extra buttons now, so I don't have that luxury anymore. I was thinking of adding a small pad to the left of my keyboard, or a big bad to replace wasd altogether, but I'm not sure what to choose from.

What's everyone here using as 'extra' keys and how are they liking it?
My setup is 1 pc with 5 accounts on it with ISBoxer.

Thanks in advance!