I've bought a black hakama for my Ichigo cosplay from this one budo store:
I train kendo and that is the main site we order stuff from. Jani-sensei was kind and let me order hakama for non-kendo purpose, as long as I don't use them for kendo practice.
However, if you decide to buy black hakama, be aware of that the himo (ties) will, probably, be black. So you'll have to either modify them a bit or make a white sash.
But yeah, that site has some good quality stuff!
(not to mention I bought the most expensive hakama on the whole site... lol)
Oh, and btw, if it helps you could check out my Ichigo cosplay
here on coscom, I have lots of pics uploaded and I'm wearing the black hakama on those.
If you need more info, feel free to PM me~
I just saw that the hakama I ordered isn't the most expensive one anymore, there is a new conqueror.
But it used to be. lol