I use a very similar setup, and I use a mouse because I've never found a keyboard I liked that includes a touch pad. I've simply taken another monitor arm + a laptop holder attachment. Flip it and put a firm pad on top and you have a mouse pad holder that you can position in 3d exactly where you want it.
I would love to use something with a TrackPoint, but I have an irrational fear of committing to a non-fullsize keyboards. It's regretful that they don't build different keyboard variants or license the tech out, but I assume the market isn't large enough to warrant more offers.
