If I were you, I'd get a DC Level 4 10" sub, it will take every bit of that 1000w your amp pushes, it will be accurate and deep.
Even less specifically, any D4 or D1 10 or 12" sub that will take 1000 watts would probably suit your desires very well.
However, you may want to consider adding more power though, you won't notice an increase in volume with that single 10" at 100w(probably a decrease actually, less cone area), but the bass will be tighter. You might want to look into getting a sub that will take 1.5-2k and spending a few extra bucks to really upgrade your system
I think most people have the ill-concieved concept of "low". You probably think a 40-45hz note is low, I bet if you tried to play a 20hz or a 25hz note with those woofers you'd hear nothing but your subs trying desperately to make an audible sound.