Better start at the beginning: what kind of signals do you want to measure? From there you can set some basic specifications for a probe. In many cases using a direct cable connection is a better option. A direct cable connection will always be superior compared to probing.
I have bought a few of the Elektor probes for a few euros each but never used them because they are AC only and need a relatively high supply voltage. A probe that can be powered through a USB connection is much more convenient.