You should probably be looking at this combo (or the board with a different combo with this board such as the RAM Combo Dominion suggested):
http://www.newegg.com/Product/ComboD...&SID=u00000687
Add the F3 Samsung 1TB disk, the i5-2400 (if you don't select the above combo), 8GB DDR3 Crucial RAM suggested earlier, and the HAF912 case you want, and you're sitting pretty under $500.
The thing is, most suggest the simplest of RAM for I5 builds because the higher speed stuff really makes little difference. Granted, the build Dominion suggest includes the 1600 speed RAM, but he also cut out the case you were looking for.
To me, you should be able to look through the thread and find exactly what you need with the information provided. There are several combos ranging from MB/CPU to MB/RAM. Should you go MB/RAM, you can pick up the i5 2400 CPU for 185 after promo code listed at the top of the page:
http://www.newegg.com/Product/Produc...-074-_-Product
8GB of DDR3 memory is an easy fix:
http://www.newegg.com/Product/Produc...-347-_-Product
Crucial for $57
-or-
http://www.newegg.com/Product/Produc...-424-_-Product
GSkill with 4GB flash drive included for $60
I would be inclined to go with the GSkill RAM, as that sits more often at $60, so should you decide to up yourself to 16GB, it'll be an easier task to find that memory for $60 than the Crucial, IMO.
As for the IGP, like most of us have been telling you, skip it. It's unnecessary.
EDIT: As for 16GB becoming affordable, well, 8GB is only $60. A little wiggle here or there on some of your parts, and you may be able to fit it in. However, $500 is just a little too tight. At this point, the Z68 platform and i5 CPU fit with 8GB of RAM, and there isn't much better you can do in your price point. 8GB should be plenty, but should you feel the need to up to 16gb, you can do it later. There is no sense cutting out a major core component (such as dropping from the i5 to the i3) just to fit 16GB of RAM in, though.