This is IMHO, so take it as you will. The Highway 1's are just a gimick to make more money, and the American's are extremely overpriced in comparison to the quality you get from the MIM's. Whichever route you got, you need to play as many of each as you can, because none will play the same as the last one you played. Honestly, if you're going to put a pickup like an Invader in it, I would just get a cheap Squire that feels good. Take a cheap Squire and an overpriced American, put an Invader in them, and I will bet money that blindfolded, you couldn't tell a difference in the tone. If you want a pickup with high output, I would look into something like a Bill Lawrence L500XL. I have a Duncan JB in one of my guitars, and it has more than enough output for any metal I want to play. It all depends on your complete setup though.

I have a friend who got a very cheap squire double fat strat, put two PRS Dragon I's in it, changed the tuners, nut, and bridge, and I swear! it is one of the sweetest playing and sounding guitars I've ever played. He might have a total of $400 in the guitar (including the guitars price), and I would put it up against any guitar costing 4 times that much.