SET 45 and their (real) required speaker efficiency

Hello,

Gosh, wasn't sure if to post in the speaker or amp sections. But here it is. 

I've got a Finale/Triode Lab F-300B Monoblock amp paired with the Omega Super Alnico monitors stated at 94.5db efficiency. It does very well with this amp and I'm very happy with the pair overall. With classical being 90% of what I listen to, I guess I haven't really pushed the system to its limits, but it delivers plenty of what I like with acoustic instruments. Harmonics (texture and timbre), tone, minor dynamic shifts (musicianship), etc.

My question is for SET 45 tube owners and recommended speaker efficiency. Do the 2 watts from these amps have a 'real world' threshold where they simply can't deliver under a certain efficiency rating? So, for example, my speakers state 2 watts and up are enough. But I've had a few people tell me that 94.5db is not enough for this SET. However, on the Decware site, it does put a pair of Omega speakers on it's site as, what I imagine being a suitable speaker to pair with their 2 watt amps. The amp I'm thinking of getting will have Hashimoto transformers and a 20 watt output transformer. Not sure if that will give a bit more for the speaker to use or not. Also, are speakers w/o crossovers something to consider if I need to go look for another pair of speakers? Finally, what would your experience with the 45 SET amp suggest as far as the optimal efficiency rating for these tiny two watts?

Geesh, it's 5:40 am, no sleep yet, please ask a question if all the above sounds like someone hasn't had sleep yet.

Anyway thanks folks, really appreciate any suggestions to an optimal efficiency.

take care,
rob