If you're going to be changing the tuning often, I'd probably definitely stay away from a trem-loaded guitar. With a floating bridge like Ibanez's LoPro Edge, once you detune one string, the rest of the srings get a little tighter, so you'll have to detune those, too. It's quite the hassle. For a fixed bridge guitar of good quality, maybe look into some of the Schecter guitars. They're made in the US and always come setup really well. This one is badass, and even comes with kickass active EMG pickups, which is what most metal guitarists prefer.