A few things to keep in mind.
Stats present a mostly reactive (ie capacitive) load to an amplifier and, therefore, operate on volts and not watts. You have to be very careful when looking at an amp’s wattage rating when it is being used to drive a stat panel. Watts is far less important than the amp’s power supply voltage rating! An amp with an inadequate power supply voltage performance will easily clip when hooked up to a stat …. despite its wattage rating.
Also keep in mind that a stat’s highly reactive behaviour means that it has weird phase angles and sends electrical current back to the amp (when signal reverses polarity). Many amps tend to be unstable under such conditions so you need to make sure the amp is stable with reactive loads.
Like with watts, more volts is always better. Especially when volumes are needed to produce live levels. For such demands, 100w will only get you into the 1,400v stator range (using 1:50 step-up) and will almost certainly be troublesome. 500w gets you into the 3,200v range which should be fine for almost all home applications.
Of course, not everyone needs or desires live level volumes so, for them, they might be able to employ a somewhat lower voltage amp. Unfortunately, the great challenge for most is actually figuring out if they are using an amp that is clipping or not.
