OK, with old equipment, you are going to run into problems and limitations. They want to to buy new stuff, you think you can keep old stuff forever? One hopes but can't in real life.
All you can hope is, with what you got, is that your TV has a analog out (stereo) and you pipe that audio to your current receiver via RCA and is gonna be stereo and that's it.
You say you want full surround? Oh well, that's a problem. TV vendors, typically don't ask me why, don't "pass thru" surround information from your external players to the TV then to your receiver, so what you have to do is, hook up the audio portion directly from the say, BluRay player to the receiver's optical in. Then you program your universal remote to send two signals to switch to BluRay, once to switch the TV video input, and two to switch the receiver's audio input. With a single digital audio input on the receiver and multiple surround players, you may have to resort to some sort of manual switcher which gets old quick.
I recommend saving your lunch money for a modern AV receiver, with multiple HDMI/optical capability.