Skite30,
It's all a matter of your listenng preferences, room size, etc., but I find the Wright Mono7s with 7 300B watts to be just fine for all but the really big and complex stuff (but we'll see how that improves once the Shuguang black bottle 300bz tubes get here). To be sure, the speakers didn't have any real limitations beyond their design limits when I used them with the Decware Torii II at 24 class A PP watts, but these drivers do have a fairly low power handling limit and a fairly low xmax, so aren't really suitable to rockin the house, and even as low as my fonkensteens go, I'm sure things will be better with some well integrated bottom end reinforcement.
But back to amps... I had an Audio Note P2SE -- 10 watt PSE el84 amp that drove them extremely well, again, certainly as far as the drivers could be pushed when run full range, and another SE el34 amp from Yarland that was rated at 10-12 watts, that also gave them all the oomph they needed.
I was also very surprised to se how well they did with my Carina in UL mode at 3.2 watts or so, and even in my larger listening room -- the living room. Again, not dance party loud, but loud and clean enough that normal conversation would be pretty difficult.
The one advantage I see to these drivers with lower power amps is that when listening at low levels at night, etc., you have to give them enough juice so that there is plenty of flux flowing in the cores of the OPTs, and thus you get a very full, detailed, and reasonably dynamic presentation. Best low-level speakers I've ever had, and that's not something very many speakers can do well, IMO.
There is also a clear and unmistakeable difference between SE and PP, and while the Torii II was a really nice sounding amp, when I switched from it to the Carina at 3 watts, it was just so much more enjoyable to listen to. Even the Audio Note, which I loved, didn't sound as clean and "right" as the Carina did, and the difference there is between parallel and single el84 output tubes. I guess the point here is that they are mercilessly revealing of everything upstream, and SE is what my ears like.
HTH,
Jim