The room is ~ 17' x 15'. It looks like you'll be sitting less than 3 meters away from the screen.
Basically any accurate bookshelf speakers will work.
Just get at least 2 subs, 4 would be better.
You could also place the bookshelf speakers on stands atop the subs to form modular tower speakers (like the $60K RBH 8T modular tower speakers).
The Klipsch KL650-THX Ultra2 speaker system is one idea. You can read about the THX Ultra2 certification. The KL650 & KL525 are among the most accurate speakers ever measured (both are +/-1dB from 100Hz-10kHz with smooth off-axis frequency response).
So you can have yourself a THX Ultra2 certified home theater sound system.
The good part is that these speakers have a dealer cost that is about 61% off MSRP.
So in hard economy times like these, you will be able to find dealers willing to help out a bro.
I would love to see Audioholics do a CEA measurement of the Klipsch THX Ultra2 subs. At any rate, you could get a great deal on the THX Ultra2 system.
Subs like Funk, JTR, Seaton, Rythmik, SVS, HSU, PSA, JL, and high-end Velodyne will also perform great.