About 30 custom guitars.
Of which the Koa wood guitar he was using in that Video is a very tight tolerance fret board, low string height, low string tension guitar.
Of course you can only do so much with a guitar...
He only looked like he was "working" at it, above 280 BPM.
There was another video from a Japanese show in the group, that showed him doing 370 BPM. They even showed the notes flying across the screen for that rate... YIKES!