Hi Bernoulli,

You are almost there with this setup.

However, I would like to add a few comments;

I think that you should get Asrock z87m Extreme4 or Z87 Extreme4 instead of Extreme3. The reason being that the Extreme4 boards come with 8 and 12 phase power systems, which is preferable when overclocking. Alternatively, Asus z87 Gryphon or MSI Z87 GD45 could be considered - both have 8 phase power design.

Secondly, with an i5 4670K cpu, I wouldn´t consider anything less than a GTX 760 GPU. If you really want to minimize shimmering, jaggies etc, high AA and AF settings would be needed, which is very hard on the GPU, and independent of the CPU. Remember, I´m here talking about Image Quality, not frames per second.
When I fly in heavily clouded areas (REX E clouds), my GTX 570 often becomes the bottleneck in my old AMD based rig... Hence, I would definately not ignore the importance of a powerful GPU with FSX.

Thirdly, regarding the harddisk configuration; A 120GB SSD for windows 7-64 bit, and a 500 GB WD Velociraptor for FSX+ addons, would be fine, and cost less than having only SSD´s.
Today I´m using a 250 GB Velociraptor for FSX, storing all my FS Global 2010 mesh and REX Essentials Plus OD on a slower 1 TB WD Black. This works fine, and loading is much faster than when I had everything on one big C-drive.

And finally, you should also consider Nick N´s Windows 7 tweaks. Made my OS much snappier, and uses less RAM.
Avsims/Kostas/Nick´s mods in FSX shouldn´t be regarded as "tweaks". I would rather call it Service Pack 3 for FSX..

Just my experience and what I would do if I should upgrade.

BR,
Anders