Maple22,
Y our math is right, 2.83v at 4 ohm load= 2 watts required at 1 meter distance. May I offer friendly advice? Try the 30 watt tube amplifier and simply judge for yourself. There can be substantial differences between two amps with identical power ratings, quality matters a lot. At CES this year and last year in the Dynaudio room( this was a very generous size room by the way) they used the tubed German Octave amplifiers exclusively on their speakers. The sound and music reproduction both years was exceptionally good. You may find you prefer tube amps rather than solid state, who knows? Just try and hear your self. You're right maple22, 86 db is pretty
loud lf you don't suffer from a hearing impairment. At your specified listening requirements I suspect you'll be fine with 30 watts ( just demand high quality well built amplifier).
Good luck,
Charles,