The Sunfire sub "might" work nice.
These are terrible terms I will use here, but you will get the gist of it...
You need something fast and dynamic to augment la scala.. Not say 4 18" overpowered Boom Boxers.Used properly, the La Scala with the Sunfire sub should be great!
Make sure the used Sunfire does not rattle or have bad edges on the cones, box edges, or coming apart rattling... Or the knobs crackle when turned.. A lot of people over use them, and blow the speaker itself.. It does go down to 35 htz... not to say 20 htz as most subs strive for today... Still not bad almost right on making a La Scala down to K horn Levels...33 htz.... But not a real earth shattering sub per say for HT, to 20 htz desired.
They sometimes can hum as well..Look at the bad volume knobs.. you wanted the good, bad, and ugly info right?
I wish u well. I know nothing about the other sub you listed, sorry.
HT: 2008 My Dream La Scala HT System for downstairs is finally 99% done. 7 Split La Scala's, (Timbre up front DOES matter!) Two Klipsch THX KW 120 subs, with the KA 1000 Amp, with the Velodyne SMS-1, Bass management system, with 2 THX series KS-525's as side surrounds. WOW! Dedicated 17' x 30' room, 106" Daylite screen, with the Infocus 7210 DLP Projector. Sunfire Theater Grand IV, Sunfire Signature series 200 x 7 amp. SONY 550 BluRay DVD player. It's Klipsch Nirvana, for me. The ticket booth is open, and the popcorn machine works, So dim the lights, on with the show!!
**NEW** TSCM bass bins with pro split La Scala tops, just for outdoor fun!