If you run them through Handbrake with the

TV preset you'll end up with a smaller file with both stereo and surround tracks. It creates the stereo track for non-surround devices like watching the movie on an iDevice. If we assume you have an

TV1, you probably have it hooked up via analog stereo cables out of the

TV to your older receiver. If so, this will work just fine.
If you have a newer gen

TV, you don't have analog stereo out. Does that Sony take optical in? If so, can you get it to play any

TV video now (such as movie trailers) and hear the stereo audio? If so, all should be fine. You'll get stereo now and be audio future-proofed with the extra surround track for the future.
If you don't have any audio playback now and have a newer

TV, you'll probably need to buy one of those optical-to-stereo analog converters to convert the audio out into stereo for your older receiver (thus, optical audio out of the

TV into the converter; stereo audio out of the converter into your receiver). OR, you could try feeding the HDMI or optical audio directly to your Television and then using it's audio out options to see if it will convert it to stereo which you can then feed back to the Sony receiver.
You may find it a better option to just go ahead and buy a new receiver. Great quality units are relatively cheap and they come with up to all of the latest bells & whistles.