Need to hookup new plasma TV with only digital audio to 2-channel receiver

Hi - I am new to the forum so will throw this out to you all. I have recently purchased a Panasonic Viera plasma TV to replace a Samsung LCD that we moved to our basement. With the Samsung I was happily using an Onkyo 100W 2-channel receiver with some decent 2-way front speakers and an NHT subwoofer and thought it sounded pretty good, even though it wasn't surround sound. Now, after setting up the Panasonic plasma, I discover that it does not have analog audio outputs, only a digital audio output. My dilemma is this: do I spend $150 to buy a digital to audio converter (found on Amazon) so I can use the 2-channel receiver I already have, or should I spend $250-$300 to buy a decent 5:1 A/V receiver which will accept a digital audio cable, even though I would only use it for a 2:1 speaker setup? My room layout does not make it "wife compatable" to run three more speakers in the room, so I need to make due with the 2:1 speaker setup. I am just now getting up to speed on the latest audio/video trends, so am learning as I go along. Thank you for any suggestions/comments you can share.

Thanks Vince. We currently have the most basic cable we can get from Comcast (trying to limit the junk my teenagers can watch!), so we haven't used a cable box yet. But, I have looked to upgrade to Comcast's basic digital package which would require us to use a cable box, and those do have RCA audio output connectors. However, I want to use my 2:1 setup mostly for DVD's, so I'll check the DVD player for the audio outputs as you suggest. I currently have my (upconverting) DVD player connected to the TV using an HDMI cable, so I could still use that connection for the video and use the RCA outputs connected to the receiver for the audio, right?
Thanks,
Ron