Keyboard equivalents to up/down arrows? In Chrome, where the autofill list can be shown with two down-arrow keystrokes, or with clicking the mouse once.

I'd like to be able to open the Chrome autofill list with some other keystroke rather than having than having to shift my hand over to the arrow keys or the mouse.

Are there any keyboard equivalents to the up/down arrow keys?
Perhaps something like ctrl+j or ctrl+k?
I doubt it, but if you are sufficiently motivated, you might be able to use ukelele to create your own keyboard layout with arrow key equivalents on them. However, note the following caveat from the ukelele manual:


  There are some limitations imposed by Apple:
  
  
  Mapping the arrow keys to something else, or other keys to arrow keys, is problematic. It will work in some applications, but not others.
  


Suddenly, this seems like a much less attractive option.