Argyrotype is so-o-o picky about paper, but I've had success with Fabriano Artistico EW after acidifying it. Bienfang 360 translucent vellum works well (without acidification) if you can handle the thin paper in your workflow.
Sam Wang gave me a good tip: dilute the argy solution 1:1 with distilled water before brushing it on the paper. It helps with bleeding in the clearing bath...made all the difference.
Also, toning argys right after the clearing bath helps keep the tone from fading in the fix.
But, there is no doubt that argyrotype can be one of the most frustrating processes...