Thank you all for your inciteful response(s). I've taken note of the subs you recommend.
Integrator proposes 1 pair Klipsch RP600M, Klipsch RP5040C, 4 Klipsch Reference in-ceiling, 1 pair RP-402 on-wall surrounds, and two JL Audio 10" dia. subwoofer driver, sealed enclosure, 750W RMS amplifier. HT room area is 25 x 20 before framing. Framing will be room within a room for reduction of sound transmission.
I fancy two subs as part of the setup but not at $1K apiece since I'm hearing impaired and wearing hearing aids. Hope to arrange direct comparison audition of differnent subs and the proposed Klipsch speakers.