Well, you've done your job well, you already know the difference in features.
I don't think there's a difference in OCing.
If you have an external hard disk and copy lots of stuff to and from it often and it supports e-SATA, then e-SATA is worth $20. Otherwise it's pointless because USB can do just as well.
Dual Ethernet makes sense if you use the PC in a LAN as a server, maybe. If it's just for your high-speed Internet access, it doesn't have to be dual.
The optical and coaxial connections are for advanced audio speakers. I have Z-5500 speakers (which are pretty much top of the range as PC speakers go) but didn't bother using the coaxial or optical on my X-Fi because it meant buying cables. I just used the cable with RCA jacks that came with the speakers and it's just fine. I suspect you can ignore this feature.
Since you care about OCing, get a HDT-S1283 instead of the Freezer.
I'll get the PQ5-E then as I have an external 1TB drive I will be moving b/w my desktop and laptop.
I'll also switch the cooler but just a quick q about that... will it fit into the COOLER MASTER RC-690?? I know that the Rifle is a pretty big cooler and some have problems fitting it. The case I have picked is ~8.4in wide while the Rifle cooler is ~7in tall... with the mobo and case clearance will that be enough room?
As for the PSU, the only difference I see is that the PC P&C has 1 +12V rail @ 49A whereas the OCZ has 2 +12V rails @ 18A each... I'm not familiar with the best designs for PSU's or good company's, I'll take your advice... just wondering if the PC P&C at $80 over the OCZ at $45 (both after MIR) is worth it?
Edit: why the PC P&C - it's the best PSU brand IMO and $80 for that PSU with free shipping is a fantastic deal. It can keep the PC from crashing better than other PSUs when there are small variations in the input current. It is rated at 40 degrees (which is more honest than at room temps) and 610W is continuous, not peak (peak is actually 670W). Finally, a single rail with 49A can support some things that the OCZ can't. The OCZ has 4 rails of 18A each, but combined they give between 35A and 48A, depending on the load on the other rails.
Mind you, the StealthXStream is not a bad PSU either, and $45 for it is also excellent bang for the buck. Plus, if you get the Antec 900 it means you like blue lights, and the StealthXStream has a blue light too.
I will stick with the RC-690. I'm not one into the whole light thing...
I will take your suggestions and get the rifle+retention bracket and the PC P&C PSU.
I had a question about RAM (after looking at the RAM compatibility lists). I found a Mushkin 2x2GB running at 4-4-4-12 @ 2.1V but it's not on the Asus board's list... should I go with the OCZ Titanium XTC 2x2GB at 4-4-4-15 @ 2.1V instead?
4-4-4-12 is better than 4-4-4-15. I don't think it really matters, but sure, if the prices are similar get the mushkin. I read the newegg reviews for the P5Q-E and there are happy customers there with both Mushkin and OCZ. Probably not the same models as yours, but still I expect yours would work too.