New build sub $1500 CS5 Computer

With a $1500 upset limit on the budget, I'd do a i7 build for CS5. I don't see where it would cost ya that much more money. The MoBo / CPU / RAM combo below is just $30 more than in your AMD build.

$474 Asus Sabertooth w/ i7-950 ($80 more than your choices)
http://www.newegg.ca/Product/ComboDealDetails.aspx?Item...

$169 CAS 9 DDR301600 Same specs but saves $50

Other considerations, mainly that 500 watts doesn't allow for "future proofing":

Consider alternate Case / PSU combos

$150 Antec P183 (Extremely quiet Case)
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

$140 Antec CP-850 (Extremely quiet PSU w/ to notch performance, easily capable of SLI)
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

Total = $40 more than your choices but you're getting an extemely quiet and cool running case w/ only 1 of the 4 PSU's to garner a 10.0 performance rating on jonnyguru.com)

HAF 922
$90 http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

XFX Black Edition 850
$130 http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

Not as quiet as the Antec combo but well cooled .... LED's might be off putting but it's $30 cheaper which would give you an i7 system at same price as your build.

I don't see the advantage to a 40 GB SSD. Windows 7 will eat 3/4 of that up.
How about an extra $60 for 125% extra capacity ?
http://www.newegg.ca/Product/Product.aspx?Item=N82E1682...

or $95 more for 300% capacity
http://www.newegg.ca/Product/Product.aspx?Item=N82E1682...

For $20, the upgrade to a 470 should be an easy decision...the 850 watt PSU makes adding a 2nd one, at a later date, no problem
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

The Antec Case / PSU Combo (+$40), the MoBo / CPU / RAM (+30) Combo, the GFX upgrade (+20) and 3x SSD size upgrade (+$95) add up to $185 extra....or $60 over ya $1,500 budget while providing substantial upgrades, an extremely quiet system and much more capability for expandability..

Thank you JackNaylorPE for the reply, this is definitely a system that is worth a look at.

Even if I don't go Intel, the tips for hard drives, cases and power supplies were all good advice and I'll try to modify the specs of the system and post an updated build.

EDIT: Would anyone else have any input to add? It'd be much appreciated!

For maximum CS5 performance:

Use a GT 240 video card w/ 1GB DDR5 (saves $), 24 GB system RAM (adds $), and Windows 7 64-bit Professional or Ultimate.

CS5 won't run faster on a GTX 460. CS5 only seems to use up to 96 graphics cores. The GT 240 also consumes a lot less power, so a 300 watt power supply would be adequate. The Nexus VALUE 430 Watt is the most quiet power supply on the planet:
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...
http://www.silentpcreview.com/Nexus_Value_430

Adding memory seems to make a really big difference in CS5 performance.

Windows 7 64-bit Premium only allows up to 16GB of RAM, so that's not very future-proof.

More CS5 hardware details here:
http://www.studio1productions.com/Articles/PremiereCS5....