Hey guys. It's always good to get an amp that can produce more than the subs can hold. That way you can set the gains and lower distortion at the same time. I don't know about that exact amplifier, but at the correct resistance, if the amplifier is able to produce more than the subs at rms, that is a good thing. So, say the amplifier puts out 1700@1. Then, to get close to possibly 1200w out of it, the subs need to be wired as close to 1 ohm as possible. If they are wired at 2 ohms, you will get around a nominal power of half that 1200 total, not to each sub. So, at ohms n you may get about 300w to each sub on a 1700w amplifier.
Now, regarding the SA12s taking that amount of power, say 800 each, that is possible, but the amount of time it will take that will depend on electrical rise and mechanical limits of the sub in a given enclosure. Free air is obviously less likely and sealed is more likely, to a point, while a proper ported will likely do it more justice thermally.
All of that being said, I cannot recommend ever going over an rms spec of any driver. Hope that helps.