Early Fender and Gibson guitars had single coil pickups,but,these would anoy people by producing hum -noticable while not playing.Fenders usually have single coils anyway and some still hum away merrily.
A humbucker is, very basically, 2 single coil pickups one of which is wired opposite to the other to "buck the hum" - thats why humbucker/humcancelling.
In addition to meng,i'd add- look at ESP (they do copies of Metallicas guitars,i do believe)Maverick and Yamaha
as they all make some suitably heavy guitars,but,BC Rich is the Daddy of the metally look.
Check out Musicians Friend (etc) for faded Gibsons at around $500. The SG is a classic metal guitar.
*..Stops himself*
Accuracy,you say? hmm interesting concept..