Considering hardware replacement

Good day simmers, for those, who do not read the post till the end, I wish all the best for the Christmas and a prosperous 2014!

Now, let's go ahead with the topic

I am considering the hardware upgrade:

- i7 K2600 -> i7 4960X

- Gigabyte GTX680 Windforce -> Gigabyte GTX Titan (GV-NTITANOC-6GD-B)

- Asus P67 Sabertooth -> Gigabyte X79 Assassin (mostly because it has a lot of USB plugs and handles them well, not like my current MoBo)

- 8 GB -> 8GB: 2x Kingston 2x2GB 2133MHz DDR3 Non-ECC CL9 DIMM XMP X2 (because I'd like to benefit from Quad Memory Channel)

Is it worth investing? Do You have any experience with quad channel memory config?

Will the 4960X need HT (I guess no for FSX)? OC?

I fly ONLY with 4x SGSS 5960 x 1080. Currently my PC handle this well, but when clouds appear (and they do in winter a lot!), my frames goes to 15-20, which is a no go.

Many thanks for all the advises.