Both are good companies, but be sure you know exactly what you're ordering before you do so. My old +3 Hakama of the Ancients was already missized and I seem to have picked up some bad wardrobe habits from it. Don't Do What Greggy Don't Does.
I don't think the conclusion we reached in the dojo the other day was that you are wearing it wrong. It is more that you wear it in a different place on your body than is anticipated by the measurement instructions. For those who have an old hakama the better idea would be to measure from the bottom of the koshita, the length to your ankle when you have the old one on instead of just from you hip bone. For those who do not yet own a hakama... maybe borrow one to try on.