PBT keycaps for KBT Pure Pro

[Xian]

Hey folks, I'm new to the scene here. I got my first mech from MD, a KBT Pure Pro backlit which, as you know, comes with ABS keycaps.
I read that it's very hard to find PBT for this model and I have no idea what to look for nor where to look at.
What PBT set is compatible with this board? And where can I buy it?
Since I will replace the standard case with a gray TEX aluminum one, it would be nice to have gray printed PBT kcaps too...

Thanks and sorry if the question has been asked before in the past.

[CPTBadAss]

There might be some sets on TaoBao/Banggood but that spacebar and the bottom right are going to be awfully hard to replace. Maybe SP has some weird sizes too? I don't have their inventory memorized.