Newbie Help - AV Receiver and PS3

[sinkonet]

I know there is a lot of opinions out there for favorite receiver brands but I'm more on a fact finding missions here. Here is my set-up, 80 gb PS3 and Sony 60" WEGA HDMI. I just got a Pioneer Elite (90 model) for a good price. I'm wondering if I should take it back and get the next model up as this one doesn't list DTS-HD and a few others.

I don't want to waste money on features I can't use. I have read here that the PS3 (my Blu-Ray) only puts out a certain format audio. So, can someone tell me what, out of the 3 million decoder formats available in a receiver, do I actually need or use along with my PS3. And how the heck does all this work together? Doesn't the PS3 decode? Therefore, is any decode in a receiver really needed. Sorry if this sounds stupid.

Here are some of the decodes out there I have to consider yet I don't know much about this stuff:

THX Select2 , LPCM Multi-Channel , Dolby True HD , Dolby Digital Plus , DTS-HD Master Audio , DTS-HD High Resolution Audio
DTS Express , Dolby(R) Digital EX , DTS-ES , Dolby(R) Digital 5.1 , DTS 96/24 , DTS(R) 5.1 , DTS NEO: 6 , Dolby Pro-Logic IIx