Woofers for Apogee centaures minors

I need information on where i can find woofers for these speakers please.
The 6 inch woofer is a VIFA P17WG-00-06 and can be found at "www.madisound.com" If no longer available, then the similar VIFA P17WJ-00-08 can be used, although you will then have to replace the woofers in both speakers, because these are a different impedance than the original, and will not match.
Call Madisound they have replacement woofers for these speakers.When replacing ; replace both woofers...i think on internet its madisound.com