Your drive plan sounds fine, although probably overkill for your current system.
If you are looking for more speed running CS6 - that was not your question, but that may be why you are spending so much on SSDs and controller - then also consider that CS6 utilizes CPU, RAM, GPU, and of course drives sometimes all at once, so if your overall performance can be impacted by the weakest link in the hardware chain.
Your current cpus, while expensive when new, are not that fast compared with newer cpus. Your RAM, at 12GB, would not be holding you back much for CS5. However, for CS6, 24GB/32GB/64GB setups are faster for many rendering workflows. Finally, you do not mention your current graphics card. Do you have one that supports the MPE hardware mode and if so, is it configured and working properly?
Thank jim for your suggestion and though,
(1) You wrote: Your drive plan sounds fine, although probably overkill for your current system
--> my question: could you explain what do you mean by that...???
(2) I intend update RAM from 12 Gb to 24 Gb
(3) Graphic card I have is: Nvidia Quadro K4000
1) Sorry, overkill = more than is necessary. In this case more drive power than would be an even balance for your current hardware list
3) Good too!