I want to OC a Q6600 and will be running a single 8800 gt with it on a GA-P35. I'm trying to decide between this one:
http://www.newegg.com/Product/Prod [...] 6817371010
and this one:
http://www.newegg.com/product/prod [...] 6817139005
 
I already know that the Corsair is a better PSU but was wondering if the Antec will offer similar performance for my needs.
thanks!

Their both Seasonic built PSUs. It's really a toss up. Here are links for you to decide yourself.
 
[H] Enthusiast - Antec NeoPower 650 and NeoPower 650 Blue
Corsair TX650W ATX12V power supply | silentpcreview.com

Thnx Zorg I appreciate.

The Corsair has a single rail with 52A. The Antec has 3 rails of 19A each, but combined they also give 52A, not 57 (you can't just add them up). Quality is similar. I'd get the Corsair since it's cheaper.  
 

^Agreed. Get the Corsair.

Just a thought - the Corsair has it's fan mounted on its "bottom" and the Antec has it's fan mounted on its "top". I forgot to mention that the case for my build is the Antec 900 which houses its PSU on the bottom of the case. I'm thinking that if I go with the Corsair that I'll have to at the very least turn the thing up-side-down - at the worst it may not work...

Corsair is probably quieter than the Antec, so another vote goes to Corsair.
 
Flipping the PSU upside down doesn't have any effect, really.

Also is this PSU a bit of an overkill given want im using it for?

A bit. 500W is enough for your system, but it never hurts to go higher, except maybe your wallet.

What do you guys think of this one:
http://www.newegg.com/Product/Prod [...] 6817163112
I think my main concern is to get a decent and stable OC with the Q6600. I also have the BFG OCed version of the 8800GT...

Silverstone is an excellent brand as well. You won't go wrong, I'm sure.

Does this build seem pretty solid to you guys? Thanks!
 
 Qty.    Product Description    Unit Price    Savings    Total Price
1  Antec Nine Hundred Black Steel ATX Mid Tower Computer Case - Retail
Model #: Nine Hundred
Item #: N82E16811129021
 
Return Policy: Standard Return Policy
 
In Stock
Mail-in Rebate
 $139.99  -$20.00 Instant    $119.99
1  GIGABYTE GA-P35-DS3L LGA 775 Intel P35 ATX All Solid Capacitor Intel Motherboard - Retail
Model #: GA-P35-DS3L
Item #: N82E16813128059
 
Return Policy: Limited 30-Day Return Policy
 
In Stock
 $109.99     $109.99
1  SILVERSTONE SST-ST56F 560W ATX 12V 2.01 & EPS 12V Power Supply - Retail
Model #: SST-ST56F
Item #: N82E16817163112
 
Return Policy: Limited 30-Day Return Policy
 
In Stock
 $94.99  -$5.00 Instant    $89.99
1  Intel Core 2 Quad Q6600 Kentsfield 2.4GHz LGA 775 Quad-Core Processor Model BX80562Q6600 - Retail
Model #: BX80562Q6600
Item #: N82E16819115017
 
Return Policy: Processors (CPUs) Return Policy
 
In Stock
 $219.99     $219.99
1  G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-2GBNQ - Retail
Model #: F2-6400CL5D-2GBNQ
Item #: N82E16820231098
 
Return Policy: Memory (Modules, USB) Return Policy
 
In Stock
 $84.99  -$40.00 Instant    $44.99
1  Western Digital Caviar SE WD5000AAJS 500GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
Model #: WD5000AAJS
Item #: N82E16822136178
 
Return Policy: Limited 30-Day Return Policy
 
In Stock
 $89.99     $89.99
1  SAMSUNG 20X DVD±R DVD Burner Black SATA Model SH-S203B - OEM
Model #: SH-S203B
Item #: N82E16827151153
 
Return Policy: Standard Return Policy
 
In Stock
 $29.99  -$5.00 Instant    $24.99
1  Tuniq T-120-LFB 120mm CPU Cooler - Retail
Model #: T-120-LFB
Item #: N82E16835154002
 
Return Policy: Standard Return Policy
 
In Stock
 $69.99  -$20.00 Instant    $49.99
Subtotal:  $749.92

^Looks good. If OCing check out :
GUIDE: Overclocking On P35-DS3L

If you need help OCing feel free to PM me .

Also if possible get this HSF: Xigmatek HDT-S1283.
http://www.frostytech.com/top5heat [...] ELHEATSINK
It's about $38 or so on Newegg, but the performance is really worth the price.

All around it looks good. Just to let you know, the WD5000AAJS is a slower driver, meant for something like 24/7 operation. The WDs ending with AAKS has more performance. The best one would the double platter 640GB.

I think you may be right about the Xigmatek. Per frostytech it would appear to outperform the Tower 120. By the way thanks to the both of you for the suggestions - they are very much appreciated! cheers-