Pass XA30.5 vs. X150.5

Completely different animal, XA.5 is Class A and the the X150.5 is A/B - 99% of people will tell you the XA.5 is the far better amps in the Pass product line. I think you would have no problem with the XA30.5 power, especially with a 40hm load. Call Pass or Reno HiFi, they will give it to you straight as to whether the match is suitable.

X-150.5 is 150W / 8 Ohm and XA-30.5 puts down 130W / 8 Ohm as tested by Stereophile.

Wow! Wonder why the spec it at 30 watts, they did say in an understated manner that it was "conservatively" rated, but that is REAL conservative. Is that a continuous power measurement or peak?

The x150.5 actually puts out 250 + watts in 8 ohms continous.
All Pass amps are pretty conservatively rated watts wise.

OP, if you do a search for XA.5 you will find a few threads that discuss the differences between the Class A and A/B Pass amps. If money were no consideration, they only time I think folks would opt for the A/B would be to bi-amplify and used as a bass amplifier where the differences Class A provides for really come through, otherwise, used full range....well, read the threads.