Need a little help deciding on a reciever

The salesman at Best Buy sold me a TV that won't work directly with the receiver I currently have, so I'm asking if there are any gotchas with the receivers I've picked below and my setup, or if there is something else to consider for the next 5 years or so.

Back story: I was given a Sony Bravia Surround sound system ( DAV140). I had wanted surround sound so I could better hear the TV without cranking it, so it was appreciated. However, my pre-HD TV didn't work very well with it. So I bought an LG LCD model 42CS570. What the salesman didn't tell me was that it only outputs via optical cable - and the Surround system doesn't do optical (and then I realized it must be an older one because it wasn't blue ray, either). It seems I should get a receiver to fix this and prevent future compatibility problems, rather than find yet another workaound.

Obviously, I'm not a power AV user; I just want to hook all this stuff up and have it work without six remotes and a CAD drawing. Besides the TV, I have a Roku 2XD, U-verse wireless and TV, and the Blue Ray player (fairly new and with HDMI port). I will use the Sony speakers for now, since I don't have a need for throbbing bass or loud sound levels. Mainly I watch TV and movies on this, no video games or game systems.

I think this receiver will work: Onkyo TX-NR515 or TX-NR616 (the 515 apparently has some reliability bug), but the whole 5.1 vs. 7.x has thrown me - will it still play just fine with 5 channels? There's also the Yamaha RX-V473 5.1-Channel that seems well rated and has the ports I think I need.

Any advice on a workable setup that I can use for the next 5+ years would be greatly appreciated. Alternately, if you can tell me where to find local AV experts/stores, that would be great. So far, what I've found is for cars, or they work regular business hours like me and their business seems more like a private office than sales. I hate to even call this a home theater, but it seems those businesses are the next step from Best Buy...

and that would be a gotcha I didn't know. THANKS! So I'm off to research a woofer...

So, how about this for a receiver: Denon AVR-1613 5.1

I can't tell from the specs or view of the back, but I don't see an output for audio, only an input - or maybe with a receiver I don't need it like I do with the Sony Bravia? Also, the speaker connections don't look like the ones I have, that pinch a bare wire. My speakers have wires; can I get a n adapter from Radio Shack or such to apply to the wire that will fit these connectors?

BTW, I've ordered a JBL SUB150P RT subwoofer... you folks are dangerous.

OK, banana plugs, right?

and speaker connections = audio outputs? Sorry for so many questions; I need a flow chart

I'm ready to return everything and go back to tv speakers. The Denon AVR-1613 5.1 arrived, but needs an ARC function to work properly with the TV - which doesn't seem to have that. Do AV manufacturers not realize they could sell a lot more stuff if it didn't take 40+ hours of research to put it together?? Just a simple chart of what connections /functions/etc. are needed from one to another would be a huge help. I obviously don't know what questions to ask or what search terms to use to find this info, if it exists. If anyone here can send me links to clear, easy instructions on how to choose that don't include 12 variations, I'd appreciate it. All I want is a decent sound system (decent in layman's terms, not audiophile terms) that works with my TV, BlueRay, Roku; not real loud, for a small room, and not for gaming.

Sorry for the outburst; Monday was an interesting day at work (it was announced that the company would be sold) and I didn't have any patience left for the AV stuff. When the setup guide said the TV only got an input from the receiver, it was the last straw - I didn't understand that the receiver handles everything and was still thinking of the TV as handling some stuff, rather than just a monitor.

I finally found a local place that helped me figure this last bit out, bought some more HDMI cables, and got it all set up Thursday. I haven't programmed any remotes to do anything more than default, but the Denon is a godsend. The setup was very easy once it was plugged into the tv, and the picture looks so much better now.

Thank you all for the help.