Those subs can be run at 1Ω each or 4Ω each, which leave you with either a .5Ω or 2Ω final impedance. Since most smaller monoblocks don't do well at .5Ω, you'll want to find an amp that does ~800 watts at 2Ω.
The CT Sounds 1400.1 will do that and a bit more at 2Ω and the 900.1 will do close to it for a bit less money.