If you’re going for a big chip and boost driver, try a MT-G2.
It ain’t a screamer, but has a great creamy-white tint and generally plays nicely with reflectors.
It made me smile. 
We all start as noobies, so it’s kind of recognizable.
Just pump enough current through them and they will push serious lumens.
But the Vf will be quite high, like close to 8 Volts.
Some boost drivers are said to be unable to drive them.
The XP-L will be the same beam pattern as it’s the same LED only warmer, obviously The SST-20 will have a smaller hotspot and less spill, more throwy basically. but it will have better colour rendition so it will be interesting to see what you make of it.
The XP-L is a straight swap as it’s the same LED so you can keep the existing A6 driver, the SST-20 should work with either of the drivers you listed, will be interested to see how it matches up with the auto-detecting buck driver if you use it.