Diggerb2,
Try viola valley wildflowers, they've got v.pubescens aka downy yellow violet. I ordered from them this spring and the yellow ones are doing good. They come bare root.
-B

This reply is coming late in the summer. I just read your posting about a source for yellow violets. I have had good luck with Gardens of the Blueridge in North Carolina. They have viola rotundifolia (round leaf yellow violet) and viola pennsylvania (smooth leaf yellow violet). Yellow violets are intriguing.