Re: I'm looking for a SQL system
Sundown and Incriminator both make good SQL woofers. I don't know what your budget is for your amps but I'd do 2 Soundqubed Q1-3500, they're rated at 4300 at 1 ohm. 3 subs per amp. They cost 799 shipped, can buy them from SSA too.
Head Unit/Speakers: Cheap Pioneer package from Walmart
Subwoofers: 2 SoundQubed HDS210s in custom 2.2 cuft box tuned to 33 hertz (I know a little small for them, had to save space.)
Subwoofer Amp: Hifonics BRZ1700. Wired to 2 ohm (1200 watts.)