If he's a beginner I wouldn't suggest a guitar with a double locking trem.
He'll spend as much time learning to tune it as he does learning to play it.
My second guitar (first REAL guitar) was a Japanees made Fender that had a Kayler made 'Fender' locking trem called a "System One"
Looking back now it was a decent trem. It wouldn't hold tune like a Floyd under real abuse since it wasn't a true double locking trem, but it worked pretty well.
It would take me FOREVER to get it in tune since I was a beginner myself at the time and had no one to show me how to set it up properly (and this was long before the days of the Internet) and I'd get so frustrated with it I wouldn't practice because of it.
For beginners always go with either a
fixed bridge, or a standard trem and be sure to explain to him/her that when you use the trem the guitar could go out of tune.
Fixed is better though, you don't want the guitar going out of tune while you're developing your ear and standard trems will go out of tune too often (even when set up perfectly) and a beginner really won't notice, and will stunt his/her ear's development.
Mic