First off, this guy obviously wants some beat to be spending 1 grand. Anyone who has answered rockford fosgate is out they damn mind. He could buy a 1k watt amp, and then have, $150 left for wiring, box, sub???? Rockford amps are for people who have basically no budget on their system and want a premium top of the line amp. audiopipe makes a 3k watt amp for $300....won't have all the fancy lights and buttons and other features, but it will crank out more power than a $850 rockford amp. audioque is also a good budget brand for amps. As far as subs, every one loves DC, they make cheap, powerful, quality subs....
If I was you, I would get two DC level 4 18's....then get the audipipe 3k watt amp. You could get all that plus wiring for your price range.
Don't know how much space you have, or if you have upgraded electrical yet, so I can't really be sure if that would work for you though.