Question...

I'm new here, so I haven't had a chance to check the archives for a similar question but...

Does anyone know where one might find knee-high rollerskates? I've always loved rollerskating, as opposed to inline skating, but I've also loved the look and support that knee-high skates give you. I can't seem to find them online even. The only thing I can think to do is to find a good pair of lace-up boots and disassemble a pair of skates to kind of... frankenstein my own.

Suggestions?

::Edit::
I wouldn't be using these for any sort of derby or competitive skating. They're primarily for a costume I'd be using frequently, as well as for simply checking out the benefits. I have bad knees and a bad ankle, so I'm interested in the support.

Also, it should look wicked cool.

Thanks for the ideas, guys, I appreciate it. I'm looking for a decent pair of boots to use, as well as checking around for a skate shop close to my location.