How would I frankenstein-build a ~20-30lbs strength "helping hands"?

I’d like a tool like a really large "helping hands", which is a soldering assistance tool with a couple of alligator clamps and lockable telescoping arms. I’d like several objects like that made of sturdier components, that can stay steady against around 15lbs-30lbs of force, and which I can use to mount things like my laptop, my phone, my keyboards, or misc other things. My primary use is moveable desk components, though.

What would yall suggest frankensteining together to build such a thing? My current thinking, which I’d like to improve on:

• I could use a monitor arm,
• attached to pieces of heavy furniture,
• then instead of mounting a monitor, mount a 5x5x2 piece of wood,
• and attach a clamp of some sort to the other side of that?

I found a build of something similar, but it’s not as heavy duty as I’d like, since my target is for it to be pretty solid against my laptop + force from my hands: https://makezine.com/projects/heavy-duty-helping-hands/ – it’s based on a household bendy light thing.

Here’s the insufficient one for comparison:

another thing I could use might be a monitor arm, but I suspect that would be overkill in some ways and insufficient in others. example pic for comparison, this one is several hundred dollars – which might just be what my desired level of capability costs in raw hardware, I’m not sure yet: