This thread may get more opinionated than which knife is best, but I shall throw in my $0.02...

Video editing = Mac.

I was always a "PC" until two years ago, and work is still PC. I have an HP Laptop that has been totally reliable. I can rely on it to fail at the worst possible moment in the field. As such, I bought a Toughbook CF-30, and have never had a dime of problems since. Well, at least until I went to work for someone else, and they issued me a Dell seven weeks ago. It has now had THREE HDD in said seven weeks. I now backup to both an external HDD and the Toughbook daily and the HP weekly, plus the company server whenever I see the office (darn rare, that).

Since you want MS Windows also (some things are windows only), get a Mac for Video editing and just run VM Ware and load MS Windows on also. The great thing about Mac is Apple Care and The Genius Bar. Online or in person help available everywhere there is an Apple store.

Failing that, make the PC purchase at Best Buy, and buy the protection plan. Most, but not all, of the Geek Squad folks are very helpful.

Frankly, given you already have a Toughbook, I would invest the $$$$$ in a good monitor, docking station, and keyboard/mouse. Coke proof, portable, and a big screen for around the office.