Hello, I have a Sony STR-K900 reciever and right now I just have the sub that comes with it and 2 cheap towers. I have all the original surround speakers but I am looking into getting either 2 new towers or a new sub. This is for my college frat room, but I still want good sound. The room is mostly rectangular and built out of concrete blocks, if that changes anything. I am not the person that wants cheap stuff so I can here to find whats best. I was looking into Klipsch sub-woofers and towers, as I have a sub at my home and it sounds really nice. The receiver has an A and B speaker hookups, and I was thinking about putting the towers on B so that I will still have true surround when I'm gaming and watching movies. I'm not sure if you have to match up impedance or wattage with the speaker ports to the speakers so again, that's why I came here. I am looking to spend about $200-$300 on a sub and about $300-$400 on a pair of towers. I was looking on eBay for better deals. All the help you could give is appreaciated.