As the original poster only mentioned audio, I would suggest going stereo for the time being. For many folks, the speakers are the main part of the system. I would spend the bulk of the money on speakers. I've made a hobby of searching for the best value in audio. Although I don't begin to think of myself as an audio expert, I do have a music degree and my ears are fairly good, if not a bit blunted by age. I agree that everyone's ears are different and my tastes will not be right for everyone. That being said, this would be my suggestion.
If your goal is audio, without worrying about video, I would suggest an Onkyo TX-8555. This is a stereo (2 channel only) receiver. You can find it on e-bay right now for $179. A great little 100 wpc stereo receiver. I have the older version matched with monitor audio bookshelves and find the set up to be a great value and excellent sound. If you must have a 5.1 receiver, I would go with the Onkyo TX-SR304. While many may find the 65 wpc too little, I've found it will make very good music at reasonable sound levels. This receiver can be found on e-bay for $150.
For speakers, the best deal out there right now is Saturday Audion's sale on PBS T55 speakers. These are great all round speakers. They are $629. If it were me, I'd go used and find a pair of Monitor Audio Sr6's. They are often found for $650. (there's a pair for that price on Audiogon right now)
For audio, I would not get the center speaker. I don't think it's needed for audio.
If you are willing to go used, I've found the best set up for audio is a used NAD C320 - $200/250, or NAD C355 - $250/300 and a used set of either PSB T55's- $450/500 or Monitor Audio S6's - $350/450(the forerunner of the afore mentioned Sr6's). I think the PSB's are a better all round speaker, especially for rock, but I chose the Monitor Audio because I listen to mostly classical.
Of course with used, you'll have shipping added to that.
Good luck shopping, and thank you for your service to your country!!
John