That's not a laptop dude. That a DTR machine: Desktop Replacement. I doubt it even has a battery - and if it does, how long would it last? 2 hours? 30 minutes?
If you're doing video editing, and lots of it, then a DTR/laptop is NOT the machine to do it on. However, if your mind is made up, then I'd add as much RAM as the machine will take, and run in RAID 0 (Never heard of a laptop which supports it, but I haven't built a laptop in the last year.) as the HDD is (normally) the big bottleneck on a laptop. Do be aware though, that RAID 0 is not fault tolerant, and you MUST use a proper backup tool, otherwise you could lose the lot.