Well, the tone in that song isn't too hard to get if you have the proper tools. Keep in mind those guitars are doubled in the recording process. That's not one guitar track. There is also bass guitar there which gives it even more thickness.
If I had to guess, I'd guess that person is tuned to Drop C and using at least 10-52's. I can't guess the pickups.
You can download the free Amplitube and it may have some metal amps on it you can use for free. I'm not sure. If you have a recording program, there are a lot of plug ins that will get you that tone.
As far as line 6, you can achieve that type of tone easily with their HD series. The HD 300 goes pretty cheap if you have cash on paypal you can pick it up on ebay. It really sounds better than the software. But the software does have some okay tones if you can find a way to buy them. Although it doesn't come near the HD series.
You shouldn't need a metal pack if that comes with just a few amps that do high gain, and possibly throw a tube screamer in front of it in the pedal section. That type of tone you're hearing is a recorded tone. Most likely through a tube amp. Even without the tube amp you can get that tone, but to sound as good as that video, that takes double guitars tracks, probably about 4 going on there. Bass guitar, and some mixing.
Find someone playing the song by themselves without a recording and you will be able to mimic that much easier. He is just playing along to a recording he did.
In recording, a lot of methods are used to make the guitars sound thick and heavy like that. It really doesn't sound like that when you are jamming out in your bedroom. Although you can get pretty close to it, minus the doubled guitar track sound.
If you got paypal, go on ebay, check out the line 6 HD500 if you can afford it, if not the HD300. It has the treadplate amp which is like a Mesa boogie rectifier and a fireball amp, both of them are some of the best metal tone's I've heard to record with. And I'm someone that has a lot of different tones at my disposal.
