OP Avoid the Kickers, you could do worse, but that's not a bad amp you have, you're better off powering two 12"s and saving your space(&peace of mind) in the long run.
What you're planning to do is buy 6 9 year old 10" 400w subs and powering them with a 1000w amp. Your basically answering your own question, but
don't know it, and if you don't know it don't do it. Do the math, take into account how much space you have in your trunk the size of the enclosure
and displacement. Subs are going to be underpowered no matter how they are wired.
Why get a 10 dollar lap dance from a hooker when you can have your own bitch, do it right.