i'd email westsounds, but peak RMS is 400 on the pro 80's. granted it's better to be overpowered than underpowered, but i would think 600x2 would not be ideal. if you run them 150x2@4-ohms, you still have 2-channels left on your amp, which is what you said you were hoping for. i am not certain, but i also think that cadence amp may be a little under rated in terms watts.
2003 X-2 MCX