I haven’t heard the SBS-01s, but based on their size I would surmise that they perform exceptionally well in spaces under 3000 cu. ft. A couple other credible members tend to agree:
http://www.audioholics.com/productreviews/loudspeakers/SVSSB01p1.php
http://forums.audioholics.com/forums/showthread.php?t=18389&highlight=sbs-01
Another on-line retailer that offers exceptional quality/value is Axiom:
http://www.axiomaudio.com/. Their M22 might work if you’re more interested in bookshelfs, but I’d prefer the M50/60 floorstanders in your cavernous space.
These few speakers recommendations are just the tip of the iceberg compared to what’s available out there: ACI, Aperion Audio, Athena Tech, Atlantic Tech, B&W, BIC, Boston Acoustics, Dali, Definitive Technology, Dynaudio, Energy, Focal/JM Lab, HSU, Infinity, JBL, KEF, Klipsch, M&K, Monitor Audio, NHT, Paradigm, Phase Technology, PSB, RBH, Rocket, SVS, Vienna Acoustics, to name a few.
I don’t know what type of surrounds you’re contemplating, but going through the attic may be the best route.