The problem we're running into is most of the manufacturers use a 95mm or 3.75" throat on the bags. If you could find someone with a mill to open that hole up, finding socks will be a hell of a lot easier.The hole they fit into is 88mm diameter. Or 3.46456693inches.
As you can see in the pic I measured the internal hole they slide into, just to clarify.
And yes, those Vertex socks are sold out all over the USA.