Hey John,
I have zero knowledge about the o-amp so I won't speak of that one.
There's a bunch of fellas on the Hawthorne site in addition to here that really love the Rythmik PEQ370 sub plate amp.
I can't find reviews per se, but here's a link to some modding a few guys are doing along with a few "shining comments" about the amp in general mixed in there.:
http://www.audiocircle.com/index.php?topic=57053.0There's also a Keiga KG-5230 that gets good reviews.
Both amps are 110-240 switchable.
Personally, I use the typical Parts Express plate amp but it's not 240volts.
Hope that helps.

Bob