Three questions on this new system configuration if you will...

I'm having a hard time holding off much longer so have been shopping prebuild machines, a first for me except for my first 486/33Mhz system way back when (4X sony CD Drive was ...$400!).   I'm aiming for a machine that is well adapted to XPlane 10 or beyond, 64bit, but will run FSX/P3D well too.  Here are the questions, and below the configuration.  Many thanks in advance for your shared insights ;o)

1. Would 32Gb of ram over 16Gb significantly lower overclockability?
2. In this type of system & application, does PCIe 3.0 add much to 'performance' in either sim?  I ask to help me decide if it's worth waiting for IB-E multi core processor primarily.  I really would like at least 6 cores, and 6 core Haswell looks a ways out.  Not even sure if IB-E chips will be overclocking friendly, or can go onto non-server, performance desktop mainboards.
3. I would like faster ram than 1600Mhz.  Can you recommend better ram for this build, speed/timing?

Specifications: 
Chassis Model: Special Deal Hot Seller - Corsair 600T <b></b>
Exterior Finish: - Standard Factory Finish
Trim Accents: - Standard Factory Finish
Processor: Intel Core i7 3930K 3.2GHz (Unlocked CPU for Extreme Overclocking) (Six-Core)
Motherboard: ASUS Sabertooth X79 (Intel X79 Chipset) (Features USB 3.0 and SATA 6Gb/s)
System Memory: 16GB DDR3 1600MHz Digital Storm Certified Performance Series (Highly Recommended) (Hand Tested)
Power Supply: 800W Corsair GS (Dual SLI Compatible)
Expansion Bay: - No Thanks
Hard Drive Set 1: Operating System: 1x (512GB Solid State (By: Samsung) (Model: 840 Pro Series) <b></b>
Hard Drive Set 2: Multimedia\Data: - No Thanks <b></b>
Hard Drive Set 3: Backup\Misc.: - No Thanks
Optical Drive 1: DVD-R/RW/CD-R/RW (DVD Writer 24x / CD-Writer 48x)
Internet Access: Wireless PCI-E 802.11n Up to 300Mbps (Supports 802.11n/g/b) (Model: ASUS PCE-N13) <b></b>
Video Card: 1x NVIDIA GeForce GTX TITAN 6GB (Includes PhysX) <b></b>
Sound Card: Integrated Motherboard Audio
Extreme Cooling: H20: Stage 2: Corsair H100i 240mm Radiator Liquid CPU Cooler (Extreme-Performance Edition) <b></b>
H20 Tube Color:- Not Applicable, I do not have a FrostChill or Sub-Zero LCS Cooling System Selected
Chassis Airflow: Standard Factory Chassis Fans
Boost Processor: Stage 1: Overclock CPU 4.0GHz to 4.4GHz
Windows OS: Microsoft Windows 7 Professional (64-Bit Edition) <b></b>
Recovery Tools: Windows Recovery Toolkit (Bundled with Windows CD)
virus Protection: - No Thanks

Priority Build: - No Thanks, Ship Within 10-15 Business Days After Order Is Successfully Processed
Warranty: Life-time Expert Customer Care with 3 Year Limited Warranty