Threshold SA/4E or Pass X-250??

Not Familiar with the Theshold, but the Pass X-250 is a newer design, more up to date.It was suppose to be the best sounding amps in the original X Series. It is not a warm sounding amp, but with a good tube preamp, I don't think there is much better out there used. The 250.5 would be better. I own the X150 with a Supratek preamp and couldn't be happier. Pass amps are also underated a lot. My X150 (rated 150 watts a channel) puts out around 250 watts before clipping. Your speakers I believe tend toward warmth anyway.
The x250 should be more than suficient. I have owned many amps, and my X150 the best I have heard.

Thanks for the info. I might hold out and try and get one of the 250.5s. The Threshold I have heard and it is something special. But it is very old, and runs very hot.

The Threshold I have heard and it is something special. But it is very old, and runs very hot.

this is normal for this sort of amp - biased in pure class-A. I believe that the heatsink fins get somewhere in the 52-54C range, which is by design.