Thanks all!
I tried the dolly zoom again today in a better setting (my desk, versus the kitchen table.) I shot it longer and in a higher resolution, so the quality is better, it has a higher framerate, and it's a bit slower. (though there are some set bumps and I had to cut it short, but eh....)
Test 2
MOL: here ya go 
It's simply the 9k on a brick base, which slides along the smooth desk. (I use the studs by the side as a measurement and to keep the camera straight.)
I never plan on buying anything when I go to the Lego Store.
Strangely enough, I always wind up finding something that makes me ditch those plans.