Laptop config

I have bought a deskstop from DS a year ago and half ago, it's still rocking.  I am currently looking for a laptop, prefer 15'' screen size, as a backup in case my gaming rig break down. 

A few things I am looking for:
-- It needs to be able to connect to my regular Monitor which is 23'' Samsung.
-- It must have enough port for my mouse and my Mic/Headphone.
-- I play WoW, so it must be able to playable with WoW.
-- Preferably also can connect to webcam.

A few questions I have, what's the different between i720Q and i820Q?  big different?
Will the config I am listing below get hot very quickly?

Ticket Number: 409509
Total Price with Instant Savings: $1,802.00

Direct Load URL: http://www.digitalstormonline.com/comploadsaved.asp?id=409509

Specifications:
Chassis: Digital Storm x15 8690 (Weight: 7.38 LBS)
Display: 15.6 inch HD+ LED Display with Enhanced Super Glossy Surface (Resolution: 1600 x 900)
Exterior Finish: - Standard Factory Finish
Processor: Intel Core i7-720QM Clarksfield 1.6GHz (6MB Cache) (Quad Core)
System Memory: 6GB DDR3 at 1333MHz (Extreme-Performance) (NOTE: Requires i7-720QM or Higher Processor)
Inputs: USB 2.0 Ports / Gigabit Ethernet LAN / V.92 Modem / 1394 FireWire / 7-in-1 Card Reader / eSATA
Main Storage: 320GB (7200 RPM) (16MB Cache) (SATA Laptop Hard Drive)
Extra Storage: - No Thanks
Raid Options: - No Thanks
Optical Drive: DVD/CD 8x Multi-Drive (Writes and Reads DVDs, CDs)
Wireless Access: Intel 6300AGN 802.11 A/B/G/N Wireless LAN Module
Features: Integrated Video Camera / Fingerprint Reader / Bluetooth
Outputs: HDMI 1080P / DVI Port / SPDIF Audio / Headphone / Microphone
Video Card(s): ATI Mobility Radeon HD 5870 1GB
External TV Tuner: - No Thanks
Windows OS: Microsoft Windows 7 Home Premium (64-Bit Edition)
Restore Kit: Digital Storm Specialized Recovery System (DVD Image Based)
Protection: - No Thanks
Office Suite: - No Thanks
Benchmarking: - No Thanks
Install/Test Game: - No Thanks
Carry Bag: Standard Carrying Bag
External Cooling: - No Thanks
External Keyboard: - No Thanks
External Mouse: - No Thanks
External Speakers: - No Thanks
External Storage: - No Thanks
Full Warranty: 3 Year Platinum Care Labor & 1 Year Parts Warranty