What ohm rating are your 12w0? They are either 4, 8, or 12 ohm. So three of them would give you either 1.33, or 2.67, or 4 ohm (all in parallel)
The 12w0 are rated for 125 rms or 250 peak each. So 375 rms or 750 peak combined.
Which Sony amp? 2 channel or mono?
So depending on the ohm rating of the subs and which Sony amp, you maybe okay.
If I were you and I could afford it the JL Audio 500/1 would be a perfect amp, no matter which ohm the subs were.