I actually found her site a while back, from an old thread here on HG.
I contacted the owner of the company, and her husband is the one that makes the racks, based on her ideas.
The old large spool rack holds spools up to 7" in diameter, but a month or 2 ago, when I contacted her, they were working on a new one that would hold a 9" diameter spool.
I don't have any 100 yd spools, but the diameter should be about 7-8", not sure.
I'm drooling over the 5-shelf rack, but I have to think about it some more, because shipping to Canada really hurts with such a bulky item
But it certainly looks like the best ribbon rack I've ever seen. =)