Is there any keyboard like that but with a touchpad below the space bar?

Rationale: I used a mouse only for (a very few) games in the last 20 years and moving the hand to reach the mouse loses time. The touchpad is good enough to select and click stuff on screen (and a touchscreen would improve the experience for a few buttons here and there.) Furthermore the mouse has literally more friction than a finger on the touchpad (the ball ages ago, the laser now, the cord, the batteries, etc)

I don't know of one, but I'm pretty sure you could hack something with a small enough wacom tablet if you really wanted. I used a wacom tablet for some time when my mouse broke and the store didn't have the one I wanted. Anyways, trackpoints are readily available and can easily be added even to custom keyboards. They're even more handy than trackpads in my opinion, since with a trackpad you still have to leave the keys while you can install the trackpoint at the hjn-join or the fgv-join (or whatever the layout puts there, for me it'd be nrt and aeä).