1. how does the present system, with the kg 4's sound to you?..........(if it ain't broke don't fix it).
The surround system sounds OK. I love the KG-4s but I have struggled a little getting the system (SC-1, SS-1) in balance. I just upgraded my old HTR Yamaha receiver with a new Pioneer Elite to see if that would help (microphone, auto calibration). That's when the 4 ohm issue started because the Elite will not support 4 ohm.
2. IF- you were to Purchase SF2s , wouldn't you need to replace your center speaker to match the SF 2? i.e. the SC2
I don't think so, Klipsch shows the SC-1 matched up with the SF-2. It is possible after hearing them together that the center may need to be a little more robust.
3. Have you tried Best Buy. com or Vann's.com , j&r music, or 6Ave electronics.com ?
Yes I tried them. The SF-2 and SF-1 for that matter have not been manufactured since 2004 I believe. They will have to be used or someone who happens to have them in a batch of discontinued merchndise.
At this point I am hoping to find out my KG-4s are 6 ohm so I can keep what I have. I have emailed Klipsch's tech support to see what their take is. I know the website lists them as 6 ohm but I guess it is possible that they were originally 4 ohm and later changed so it would depend on which one you have. I am trying to get a decent system without having to put to much more $$$ into a line that was discontinued years ago. At some point you just got to start over....$$$$$....ouch. The biggest problem right now is I just don't want to box up my KG-4's, period.