arrow keys, page up/down keyboard

I want to move my Trackball as close as possible to my right hand. So I
want to either saw off the keyboard to the right of the Backspace key or
remove the keys and place my Trackball on top of the keyboard beside my
right hand. Either way, I need to remap the arrow keys and Page Up/Down
keys. The first priority is the arrow keys. Or I need to buy a mini
keyboard and place it on the left side of the keyboard. Any suggestions
for a mini keyboard without the numeric keypad? Another idea was to use
a generic keyboard on the left side of my main keyboard and just saw off
the numeric keypad - thereby placing the arrow key area beside my left
hand.