You might be able to save a few Dollars since FSX doesn't really benefit from a SSD. So as long as they are relatively small for their price, you might be better off with a large normal disk. Now the OS is very happy about a SSD while 120gb variant for a FSX installation can run out of space pretty quickly. I'm thinking of large photo sceneries or a lot of liveries for your planes. CS offers a lot.  :D

To expand on the performance gains (or lack of). You will see nice loading times with a SSD for FSX but the actual ingame performance and even the texture blurry problems aren't affected at all. Now a SSD doesn't hurt but you are spending a decent amount of money for close to zero overall gains. Not to mention the lack of space.

Perhaps you can alter the NVIDIA GeForce GTX 650 to something like a 660, 660Ti or 760. If you are running antialiasing settings with FSX, you will see a better performance (which actually just means less loss) with the 660 and above. The 650 is very limited in that regard and lacks of memory bandwidth for example. Should be most noticeable in clouds as those drain a lot of fps when being run with higher antialiasing settings.