I'm interested in getting some Polk Monitor 70's for some fronts, stereo listening for now. (Don't have an amp picked out yet) I am wondering if it I should add a Polk CS20 for a center channel to start with? I'd don't think I want to add a sub, not nor in the future. I'd rather get some monitor 50s to the sides? For now, I'd like to start with just the monitor 70's in the front. Would it be beneficial to start the setup with a center channel too? Is it even possible? Would you just simply set this up as a 2 channel setup with the 70's only? Start with a 5.1 amp and run the fronts and center? Or is it better to get the fronts only and get the center when I can get the sides? If you feel like offering any more help, any 5.1 amp suggestions? Movies, internet and music will be coming from a PC with a optical/3 color audio out and an old video card with just s-vid, component and composite out. Of course this will change into the future.