Yes, carefully placed multiple subwoofers is the way to go. Read Floyd Toole's "Sound Reproduction" to learn about inherent bass peaks/dips in residentially sized rooms.
For music/speed most go for sealed subwoofers. Rythmik L12 is sealed, servo controlled, goes down to 18 Hz (-3 dB), is compact, and sells for $559 USD (free shipping in the lower 48).
For more connections/features look at PreSonus T10 ported subwoofers, goes down to 20 Hz, is relatively compact, and sells for $429 each.
I use 3 subs in my 8ft x 13ft x 21ft room (two are T10's) and they offer plenty of performance.