I good upconverting player like one of the Oppo ones is going to cost about the same as an HD-DVD player that can upconvert as well. I'd say it's the way to go.
Even if HD-DVD "loses", you'll still have a good upconverting player for SD DVDs and there are already a significant number of HD titles out there already to watch as well.
Crutchfield was the place selling them for $199 and it looks like they raised the price. I'm not sure if there is a new place to get the deal.
For the speakers, they're all made by Polk, but I honestly think they're not matched very well.
You have the old R-series up front, the old R-series behind, and the RTi/CSi series as the center.
Crutchfield goes through the voice matching on the centers as well here
http://www.crutchfield.com/S-x...archDisplay=Polk+Audio
I still think the CSR is the center that's supposed to match the R-series the best, not the CSi25.
That said, you also have different colored speakers in your system too. I don't know if that's something that matters to you or not.
R300s up front with R150s as surrounds and a CSR center would match better aesthetically and sonically imo.
I agree with venkman about picking something other than Polk for the sub. At this pricerange, the dayton subs for a new one are a good option and should be better than the polk options.
If you're willing to go used, you can get much better bang for your buck with something like this
http://cls.audiogon.com/cgi-bi...pl?homesubw&1187056498
The only reason I'd get a receiver like the Onkyo 605 right now is if I knew I was going to be using some kind of HD player. If you're not going to do that right away, then I think the point of getting it is rather lost. Features are constantly getting more affordable and moving down through product ranges to the lower end models.
If you're just going to have a single HDMI source in your system and HD audio formats aren't going to need to be played, then you could just run that single source to your display and just run audio to the receiver (that's what I'm doing with my own upconverting DVD player).
I'm not saying that buying a receiver with HDMI audio capabilities is a bad thing to do, but rather that I think spending half your total system budget on your receiver isn't the best way to go when the main feature of it is something you might not even use.