Two EDK's would be more than capable of running 1200 watts RMS, so getting two wouldn't give you as many problems in terms of wiring configuration.
But if you already have the enclosure for three, get the dual 2 ohm versions. Wire the subs all in series to get a 4 ohm load per sub, then wire those in parallel to the amp to make a 1.3 ohm load (number of ohms/number of coils)
Amp for 2 subs - ED Nine.1, JBL 1200.1, Phoenix Gold Tantrum 1200.1, US Acoustics USX 1000D
Amp for 3 subs - Cadence Z7000, Adire/Ampman Revolution 1500.1, RE 35-1D, SoundStream Picasso 1700D