Starting a second system, need efficient speaker suggestions.

What sound characteristics are you looking for, and are you looking for new or used?

Even tonal balance, good dynamics, the ability to "disappear". New or used.

First: triode better?

Me, and everyone prefers Ultralinear to Triode here, You will find reviewers saying this and that. I think you can plan on your amp sounding great at 80wpc. You might find a particular type of recording that you prefer triode, but I am sure you will use Ultralinear primarily

at 7' high ceiling, I would not go for a big woofer,

these on ebay

B&W Nautilus 805

should sound great, and if you want more bass, sub's it is. I recommend self-powered, stereo pair, front firing, located adjacent to the mains. Bass directionality comes from the overtones, 40, 80, 160, 320 .... 

Sensitivity: 88. That is a bit low, you will be ok,

however, if you use subs, and you remove the low bass requirement from the amp, i.e. pre-out, crossover in sub, back to amp, amp now sending only upper bass, mids, highs to the b&w, the 80 wpc will be plenty.

IF you live near Cary, NC 

infinity kappa 9

klipsch forte II

free shipping

I would have seller clarify:

"NEW RESTORATION FROM KLIPSCH RESTORATIONS "