If you search a bit, many people ask for amp comparisons in the 2000w @ 1 ohm range.
I'd go for the Audioque 2200D, MB Quart DSC2000.1D, or Lanzar Opti2000d. All are excellent quality (capable of 1/2 ohm operation, though MB-Q is unproven) and will give you the power you need for minimal cash.
If you do overpower the subs, just keep the gains set for 2000w (45 V AC) using the tutorial.
As Dady sez, do your box right, and it'll make more of a difference than the amp choice. 1.2-1.6 cf, tuned to ~40 Hz.