I ran into the same problem when putting my system together and I came up with a few solutions.
1. Run a good reciever and use the speaker outputs as your pre-amp which will allow you to control what speakers are being utilized by what speaker mode(stereo, 5.1, ect.) you have selected. You can take this one step further and buy a yamaha reciever which has 5 channel stereo
2. Use a surround processer and a/v selector box to switch the imput signal going to your amp.
3. Turn off the surround amp when listening in stereo
I hope these ideas help point you in the right direction
1. Run a good reciever and use the speaker outputs as your pre-amp which will allow you to control what speakers are being utilized by what speaker mode(stereo, 5.1, ect.) you have selected. You can take this one step further and buy a yamaha reciever which has 5 channel stereo
2. Use a surround processer and a/v selector box to switch the imput signal going to your amp.
3. Turn off the surround amp when listening in stereo
I hope these ideas help point you in the right direction