Do you know what kind of pick holder is the one on top of the Voodoo Labs Pedal Power 2+ in Thom's pedalboard? I'm looking to buy a pick holder for me, but I can only find ones for mic stands or for straps. As I don't sing and also don't like the latter, the one he uses would be perfect for me.

I am not quite sure what it is, but I think that it is simply a generic one which is meant to be used for a mic stand. Likely, there’s just a bit of velcro on the bottom to hold it in place. If that isn’t what Thom’s doing, it would sure be a quick solution. Considering that these holders seem to be made of rubber, you could also just cut off the bottom part meant to hold it to a mic stand and velcro the then-flat bottom wherever you need.

Depending on if you use a pedalboard, and then the type of pedalboard used, one of Thom’s older solutions (employed from 2006 to 2010) might work for you. As you can see in the image below, Thom simply clipped one of those pick holders made for a mic stand onto his pedalboard. This specific idea may not work with your setup, but perhaps something similar will.

What you’re looking for doesn’t seem to be out there, but one way or another you should be able to adapt some existing product to suite your needs!