I'm thinking of doing the 7500 now that you mention it, did alittle research, the 12" 7500 is 400rms, my amp puts on 400x2 RMS @ 4ohms, bridgeable to 800 x 1 RMS @ 4 ohms, i think i'll get 2 12" 7500s dual 4 ohms, wire them each down to 2 ohm and run them to there own channel, this way i'll be giving them there perfect RMS as well as Keeping my amp a little cooler then bridging it...
2 12" MTX Thunder 7500's for 270 on ebay...thats not a bad deal...for the price difference between the 7500 and the 8500, i think i'll go with the 7500, 2 of the 8500 would run me over 400 bucks...