New 17inch laptop

Hello,

I am new here, and am looking for a laptop.  After looking at every manufacturer I decided to use DS.  Mainly because of the great community and the price is very reasonable for a high quality system.  Here is the laptop I am looking at....

Specifications:
Chassis Model: Digital Storm x17 Laptop (Model: 9170)
Display: 17.3 Inch (16:9) (Resolution: 1920 x 1080) (Glossy Surface) LED-Backlit Display
Processor: Intel Core i7 3610QM (2.3 GHz Turbo Mode to 3.3Ghz) (Quad Core) (6MB Cache)
Thermal Compound: Premium IC Diamond CPU and GPU Thermal Compound (Reduces Thermal & Laptop Noise) <b></b>
Memory: 8GB DDR3 1600MHz
Primary Hard Drive: Intel 240GB SSD (520 Series) (SATA 6Gb/s) <b></b>
Secondary Hard Drive: - No Thanks
Optical Drive: DVD/CD 8x Multi-Drive (Writes and Reads DVDs, CDs)
Wireless Card: Bigfoot Networks Killer Wireless-N 1103 (Reduces Latency for Online Gaming) <b></b>
Video Card(s): NVIDIA GeForce GTX 675M 2GB with NVIDIA Optimus Technology <b></b>
Windows OS: Microsoft Windows 7 Home Premium (64-Bit Edition)
Warranty Plan: Life-time Expert Customer Care with 3 Year Limited Warranty

$1996

Rules of this build are as follows,

Wife says it has to stay under 2k

It is used for gaming only and to watch online video

Questions I have are as follows

Is the Diamond thermal necessary?  I for some reason need to be convinced to spend that extra 35 bucks

Does it void the warranty to install a HD myself?  Reason I ask is because with the 2k budget, I would rather buy the 240GB now and add one whenever I need another.  I figure 20GB per game, if I have 5 loaded up at a time, i should be fine, I usually delete the game after I tire of it, and usually only play 2 or 3 at any one time.  I don’t want a HDD. 

Thanks for your help!