Odd the link works for me? Not endorsing the generator mind you, just pointing it out.
You may be right about the 50 to 60 volt supply with a current capable of 800ma being just fine. You are certainly right about not needing an arc. However, if you want the very smallest particles and thus greater surface area per PPM - whether it be silver or gold - then the arc is the way to go along with a few other refinements.