Best Subwoofer(s) for SF Guarneri Homage

Recently purchase a pair of Sf Guarneri Homage's. I knew i would need a sub (or two) eventually, since my musical tastes spans range from chamber music to rock. My room is dedicated but small (12.9 x 14 feet with 8ft ceilings) I am still working on speaker positioning to get the 40 hz and up range just right. Rest of the system is full blown LP12 (Lingo, Ekos, Arkv) into a Linto pre-pre into a BAT VK5iSe, into Bryston 7B ST's. Interconnects are Emerald x3 (all balanced except for tonearm cable and pre-pre tp pre) and speaker cables are AQ Argent in a bi-wire configuration. Digital duties performed by A Muse 8 into a Muse 296. Have heard good things about REL, but no way to audition (no local dealer).. so thinking of going the Velodyne HGS route. Thoughts? This is a "first iteration" system cobbled together "on the run" as I moved back to the US last month and had to jettison most of my 220 volt equipment, so any comments/thoughts beyond the sub are welcome!! I find the tonal balance a tad bright, and the SFGH's don't quite "click" unless pushed fairly hard (95 dB peaks or so measured from the listening positioning). Thanks! Alex