Do you have any other input besides that thread on receivers, I know you are a Denon man, but I was reading that thread for about 2 hours last night and everyone has a different opinion on everything, thats why it's so tough
Honestly, they are all good choices and I'm not really a brand fanboy. The best way to decide on a receiver is to understand what features you need and/or want, which is why I recommended reading through that thread to see what kind of features are factors in other people decisions. Here's a suggestion: read through the thread with a piece of paper handy and write down any features that are mentioned that look important to you. e.g. number of HDMI inputs, ability to convert analog video to HDMI output to the TV (if you only want to run one HDMI cable to the PJ), auto calibration, ipod USB port, whatever.
I am personally a big believer in Audyssey so that is a factor in my decision. It's available in Onkyo models (70X and up), pretty much all Denon models, as well as mid-level and higher Marantz receivers. But the Pio MCACC system gets good reviews as well and it has a feature (the USB port) that may be the "killer app" for your setup. I don't care about that as I use an Apple TV to get all my music to my stereo, which is an example of why you need to understand your owns needs in order to pick the receiver that is right for you.
ultimately you will just have to go with your gut. Like I said, thankfully there aren't many bad choices. The best bet may be to order the speakers/sub first, and then bring home a receiver from Best Buy and try it out with your system and see how it sounds.
any of those subs better than the others or are they pretty much the same in quality
They are just different, but they are all totally awesome. Again, you may just have to go with the one that "tickles your fancy". You are the one who's going to have to look at it every day in your room
I honestly don't know that much about the eD and HSU -- other than that they come highly recommended. When I bought my sub (the VK-12) at the time the eD and HSU were not available as cheaply, so that was the deciding factor for my decision.
I suggest you go to the subwoofer forum and browse through the last few pages of posts... any time there is a thread with a title like "best sub for $300??" or "best sub if I'm on a budget?" click on it and read. You may also, after reading a bit, want to post a thread describing your room and asking for recommendations. You may want to be flexible on the sub budget and push it to $400 depending on the recommendations; you have a fairly large space so be flexible.
But the Energy C-Series setup will be a great start! Good luck!