Buiding A Fast Machine For Panoramic Photo Editing with Photoshop CS6

Hi All and Happy New Year

I want to rebuild my pc for editing Panoramic Photo. My pc worked fine until i started doing these large file editing.

My current pc setup:

• Gigabyte Z68AP-D3
• Intel i7-3770 processor
• 16g RAM (8g Kingston 1600MHz DDR3 x 2)
• Sapphire HD 7950 Gpu (OC to 950/1350)
• 1T HD for W7 Pro 64 and other
• 1T HD for Photoshop CS6-64/Lightroom4-64/photo file
• 120g Intel SSD as scratch disc for CS6
• Mostly work with Sony Nex7 RAW file (convert to DNG when import)
  

Anytime I work with more than 3 layers the machine runs very slow. e.g. applying tonal contrast in Color Efex Pro thru CS6 plugin would take more than 8 minutes; whereas with single layer only takes 5 sec. I need to constantly merge layers and which forbid me to go back to work on previous adjustments if I find the result not satisfactory.

After some searching on the web I found some possible solutions

• Run Win7 on SSD Raid0
• Use more RAM i.e. 64g/32g ( which seems to require an upgrade to MB with Z79 chipset)
• Upgrage Cpu to i7-39xx
• Max OC current processor
• Add a SSD for current project

I don't know how sounding are the above suggestions. Would someone with solid experience working on large pano file or similar enlighten me. Many Thanks