I didn't actually mean for that to sound as rude as it sounds when I re-read what I wrote earlier. I've just felt like absolute garbage for the past couple of days (think I might be coming down with the flu) and my patience is short. I'm sorry for how that statement came across. :P
Anyways, I think the way to get the half and half priest sig you're looking for is to make it in the white/gold color that you're looking for on the "light" side and then duplicate the layer and crop it so you only see half of it and either recolor that layer using Control+U to the purple shade you like or using a purple photo filter over it set to the intensity percentage that you like the best. I know Aryiana used to make some gorgeous sigs like that, maybe she can shed some light on her method for us?