I had used Antique Sound Labs Explorer monoblocks (about 45 watts SET based on the 805 triode) to good effect with Spendor SP 1/2E's in a small room (156 sq ft). The Spendor's are 88 dB sensitivity. I never ran out of volume with that combo. I play mostly classical including large orchestras at realistic volumes. This amp was given a very positive review by Art Dudley some time ago in Stereophile. A good and relatively inexpensive way to try out SET. Good luck.
Mark
Mark