This will "do the math" for you
http://www.antec.outervision.com/index.jsp
This will help you pick it
http://www.silentpcreview.com/Recommended_PSUs
tell me the difference between a modular and non-modular psu?
Non modular - very hard to find outside of real cheapo models.....essentially every cable is permanently attached to the PSU and you have to bundle up and hide all the stuff you won't use. Example of this type Rosewill Xtreme Series RX850-S-B.
Modular - no cables are permanently attached to PSU ....plug in what ya need....rest go back in the shipping carton. Each connector adds a bit of resistance and drops efficiency a tiny bit. Logic of having any necessary cables modular escapes me. What's the point of adding a failure point, the extra cost, decreased efficiency and the resistance of a connector if you absolutely must have that cable connected (i.e. 24 pim MoBo power cable, 8 pin EPS cable, 1st SATA and 1st e-SATA cabe) ? Modular cables only make sense when cable is optional. Example of this type HX850
Hybrid Modular - best of both worlds .... all absolutely necessary cables are hard wired and permanently attached to the PSU. All optional cables are plug in type meaning if you don't need the cable, you leave it in the box it shipped in and put it in your closet. Examples of this type Antec CP-850, XFX 850W Black Edition
As for choice of PSU, what I'd recommend depends on what case you choose. Best price / performance would be the Antec CP-850 (10.0 jonnyguru.com rating) and Editor's Choice at silentpcreview.com but it only fits in 5 Antec cases (P183, P193, 1200, DX-30 and DX-85 ... last 2 you can't buy yet). Great combo deals available on these combos. Given you stated intention not to OC and single GFX card, I'd recommend the extremely quiet Antec P183.....serious OC's and twin GFX, Antec 1200.
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.387490
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.387037
For comparison purposes , the list below contains performance ratings (10 scale) at jonnyguru.com / prices as per newegg on 02/21/2010 and ones w/ double asterisks (**) made it onto silentpcreview.com's Editor's Choice List meaning they excelled at both electronic and acoustic performance:
Antec SG-850 - 10.0 ($220) **
Antec CP-850 - 10.0 ($110) **
XFX 850W Black Edition 10.0 ($185)
Corsair HX850 850W - 10.0 ($180)
Antec TruePower Quattro (TPQ-850) - 9.5 ($150)
Corsair TX850 - 9.5 ($140)
Seasonic M12D 850W - 9.5 (NLA) **
NorthQ Giant Connector 850W - 9.5 (NFS)
Etasis ET850 - 9.5 (NLA)
Silverstone Zeus ST85ZF - 9.5 (NLA)
Enermax Revolution 85+ 850W - 9.0 ($250)
Thrmaltake Toughpower XT 850W - 8.5 ($216)
OCZ Z Series 850W - 8.5 ($200)
NorthQ Black Magic Flex 850W - 8.0 (NFS)
Coolmax CTG-850 - 8.0 (NFS)
SilverStone Decathlon DA850 - 7.5 ($230)
Enermax Galaxy DXX 850W EGX850EWL - 7.5 (NFS)
SilverStone Strider ST85F - 7.0
Silverstone Element ST85EF 850W - 6.0
NFS - Not For Sale / NLA = No Longer Available
The 850 watters run almost the same price as the 750 watters so I say why not get the 850 and have the cushion. Keep in mind that PSU's reach their peak efficiency at 50% load so the extra room also pays dividends. If you're going to do twin GFX and serious OC'ing, I'd recommend the bolded ones in the list above. With one GFX card and mild OC or two GFX cards and no OC, one of the underlined ones will suffice.
You don't say what you're gonna be doing with this PC but I'd be right surprised if RAID 0 did anything for you. Other than movie editing, manipulating huge databases and other extremely specialized applications, RAID 0 does butkus on the desktop.
I much prefer the Asus P6X58D (dual LAN) or P6X58D-E (Single LAN) over the X58A-UD7 .
The Dominators heat sinks may interfere w/ any 3rd party CPU cooler.....not much of an issue as you don't appear to want to OC...the stock Intel cooler will be fine then. In any case, with the money you're spending on the rest of the stuff, I'd be using CAS 6 memory
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226121
The Noctua came in 18th place here, why not the comparably priced No. 1 Megahalems ? Then again, if not OC'ing, you don't need one.
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=492&Itemid=62&limit=1&limitstart=4
For the price of those 3 Gb/sec WD's, consider some 6 Gb/s drives .... for example
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148506
No, a single SATA III drive won't benefit for disk transfers but transfers from cache certainly will ..... also in RAID 0 as you plan, 4 of them certainly would ..... however both the Asus and Gigabyte UD7 boards only support two SATA III connections w/o an add on card.
Blue Ray:
Fastest Blue Ray Writer in existence
http://www.newegg.com/Product/Product.aspx?Item=N82E16827249057
My fav BR Reader / DVD Writer
http://www.newegg.com/Product/Product.aspx?Item=N82E16827249050