Yeah I would suggest you stick some wood on your left side of your current keyboard, for a few days to see if you can adapt... I always used that space as a resting place, so having it occupied totally broke my flow.

(If I needed a numpad I would have it standing alone.. those are easy to find)

Like I said, I'm already using a separate number pad on the left.

It's easier to adapt to than than putting the mouse in my left hand!