DIY active / high impedance probe design

The “problem” I’ve been wanting to have an high-impedance (Hi-Z) probe for some time now. Up until now I’ve been searching for something like an HP 85024a which comes up on the second hand market from time to time. It would be overkill for my needs, but still nice… :) Recently I came across an old Elektor/Elektuur article from April 2004 titled “Poor man’s 1GHz active probe” by David Jewsbury. Some more research turned up the bachelor thesis of Thomas Hirschbuechler titled “Design of a low-cost 1GHz active probe”.