Lloyd,
I too really like the sound of Strads. I hope you find an amp that really works well for you. The Strads do not strike me as being particularly tempermental so you should not have too much difficulty finding a good match.
Let me make it clear that I have not actually heard an Atmasphere amp with this particular speaker, although I've heard and really liked their amps in general. I've also heard, and liked the Joule OTLs. The Joules struck me as being warmer sounding (richer upper bass), but the particular unit I heard had problems with bad tube sockets (caused an intermittent, but extremely loud BANG), so I can recommend Joule on sound quality, but I would be concerned about reliability.
I am generally partial to OTLs when it comes to higher power from tubes. I personally have found some higher powered pentode tube amps to have a brittle edge to the sound and a "glassiness" that is worse than most solid state amps. OTL's can sound a bit rough and tumble and they may have a bit of brittleness too, but, the compensating payoff with OTLs is their unmatched liveliness and vividness.