@Loudxmouse: Here's the links to the two pages I got my feathers from on that site. It's a pain to manuever, but after some research, they really are pretty cheap, and have a good selection!
Peacock Feathers (I used green gold) - http://www.tonyhill.net/productCat101743.ctlg
Pheasant feathers (Everything else) - http://www.tonyhill.net/productCat101744.ctlg
@lroscishewska: The colored ones I used are from here - http://www.tonyhill.net/productCat102094.ctlg
(You buy based on size, I'm pretty sure I used 8-10" and just trimmed them as needed on the bottom, it seemed to make them fluffier at the top)
Hope that helps!