As of now, I can't really find a better deal on laptops with all this for only around 500. Those HP DV7/DV6 laptops really pack a punch. I know they overheat, thus I'm getting a cooling pad.
Simply buying a cooling pad is not an ideal solution. The idea solution is to stay away from laptops that are known for overheating issues because sooner or later you are going to run into problems.
I would recommend the following refurbished HP Pavilion dv6-6135DX for $530 + $15 shipping. It has a quad core AMD A8-3500 @1.5GHz and Radeon HD 6750M graphics card. The CPU is somewhat weak compared to a laptop with a dual core Intel i3 CPU so video editing will not be as quick if you were to go with Intel. However, the graphics card is pretty potent. There are no complaints about overheating with this laptop.
Alternatively, the following new Lenovo IdeaPad Z570 has a dual core i3-2330 @ 2.2GHz and a nVidia GT 520 graphics card. The Core i3 is more powerful than the A8, but the nVidia GT 520 pale in comparison to the Radeon HD 6750M because it is a budget graphics card being compared to a powerful mid range graphics card.
Since the laptop version is basically the same architecture as the desktop versions all you need to do is adjust for the CPUs' speeds to get a rough estimates on the benchmarks. The difference in clock speed of the desktop A8-3850 and the mobile A8-3500 is 1.4GHz; that means the mobile A8-3500's benchmarks should be 52% of the desktop A8-3850. The difference in clock speed of the desktop Core i3-2100 and mobile Core i3-2330 is 0.2GHz (200MHz); that means the mobile Core i3-2330's benchmarks should be 94% of the desktop Core i3-2100.
Looking at the x264 HD Encode Test - 1st Pass, the Core i3-2330 should be able to achieve about 65.1 frames per second. However, the A8-3500 will only be able to achieve about 30.1 frames per second.
The Windows Media Encoder 9 X64 test shows that both the desktop versions of the CPU were able to complete the test encode in 32 seconds. With the difference in clock speed, the Core i3-2330 will be marginally slower at 34 seconds, while the A8-3500 will need about 61.5 seconds to complete the encode. That's nearly 2x as long as the desktop version.