Where can I find radical clothing like that displayed in Zoolander by
Derek Zoolander (Ben Stiller) and Hansel (Owen Wilson)?
'Over-the-top' clothing (ie Derek Zoolander's red shiny outfit) is my
thing.  Thanks a lot!

You might try a fabric shop and a seamstress.  If you take a look at
the patterns--clothing and costumes---pick out qualities of several
patterns you like, and choose your fabric, a good seamstress should be
able to sew it for you, for much cheaper than you would buy it for. 
If you can't find a seamstress ask the woman at the counter of the
fabric shop, i bet she sews.