Yes, but Earsonics tips are better than most. Their dual flange tip has a larger bore than many, including Shure & Westone. Other similar are Sensorcom dual flange and Futuresonics dual flange. But I think they're both outside the US, too. I've ordered from all 3, and never had problems. Just make sure u don't get the upgraded mail service, as that seems to take substantially longer to make it to the US.
Also, I just ordered some dual and triple flange tips from a place called earphonesplus.com. They seem to be a litte different style that I haven't seen before, and appear to have a larger bore, too. Haven't arrived yet, though, so don't know for sure. If they do, the triple flange will be rather unique, as I haven't seen any other triple flange with the larger bore.