Would like to be able to test the lead levels in different water sources (home, work, school, friends... )
And willing to pay for it
Wondering which machine/test stripe should I buy?

From a chemistry point of view, you can try sulfuric acid, or any other solution with sulfate ions.

If a white precipitate (solid) is formed in the solution (preferably clear transparent before testing), then lead is present in the water.

Caution should be taken though if you use sulfuric acid as it is corrosive.

It really doesn't sound like this method would show anything in the PPB range which is where I expect most water sources to be in( I think 50 PPB is the CA legal limit for drinking water)

Maybe you could ask this question in the plumbing area?

Yes, I didn't know the magnitude of the concentration concern, I'm sorry about that. My method would require a 500 mol/L concentration of acid for a 1 ppb concentration lead :p

I tried Google and there are some interesting links coming up. I 'm sorry I can't help you here :(

I'll ask for your question to be moved to the plumbing area. Is that okay with you?

Yeah sure
Thanks man
If I remember my chem classes well than the maximum mol/L for simple acids is in the low 10s