You are attached to your KG4's for the same reason I am to mine, they are great! They are not too picky about what drives them, but a crappy amp will still sound like crap.
After two years with my KG4's here in Korea, I bought a pair of ChorusII's in '04 (after 8 years of searching) and temporarily retired my KG's because I was still "2-channel". Then, after a move in '05, I finally bought a 7.1 Yammie HT receiver. What to do, especially in my dinky apartment? Hook everything up, of course!
The ChorusII front channel and the KG4's in the rear works great! Above about -15db on the Yammie's dial, the combination literally shakes the floor. Five appearances by the Korean National Police so far. Even though they were never intended to work together on the same system, they really complement each other well in my room.
I stopped considering a subwoofer for this setup, one of my friends with 4 ForteII's tried and he lost bass! I've got plenty, just ask the cops! Might want a center channel someday, though. No rush.
For me, going HT has NOT been a reason to part with my KG's, they aren't going anywhere! In your situation, where I would place the KG's would depend on what other KLIPSCH speakers you plan to use with them. For instance, if you picked up a cheap pair of KG2's, try the smaller speakers in the rear. If you invested in some Fortes or Chorus, move the KG4's to the rear.