AC line conditioner +dedicated outlet

Only surge supression won't improve sound of your system you need to low RFI EMI so Quiet lines or power line conditioner are a better option

Well you have some very nice equipment.(well it's every thing I got except for I have ATI 1505, and 45 inch TV) I'm not sure you really need a line conditioner. So I would take a look at a Panamax 1000+, it is a Surge Supression/Line Conditioner and it look pretty nice as well. It comes with several Million dollar equipment Guarantee. You can pick it up over the Web for about 200 bucks.

You seem to be making an assumption that your wall faceplate is a dedicated circuit. Unless you required your electrician to install it this way, it most likely is not and is shared by other faceplates in your home (the number depends on local code). The danger here is noise from other devices and voltage sags. In the early evening (and when your air conditioning is on), check your voltage at different times with a radio shack multimeter when your system is on. You should always see 115 volts. If you see less, you may improve your sound with installation of a dedicated circuit, and further, specify 20 amp, and isolation grounding to further reduced noise and lower cable resistance (common in commercial and computer applications). Then, get a quality filtration/conditioner device to plug in all of your equipment. This all really helps and the circuit should cost between $90 and $150 depending on how much effort to get the wire to the faceplate location. I am not a tweek-freek and think alot of that stuff is a little silly but I am really big on good, clean power. It has made big improvements for me in all of the places I have lived.