https://www.amazon.com/XVX-Low-Profile-Keycaps-Keys/dp/B0BVYV67QS?ref_=ast_sto_dp&th=1
Well there is this set available on Amazon. I haven't tried it, but it fits the bill of being low-profile, PBT and shine-through. You will want to check the Q&A as there seems to be some confusion over whether the space bar fits exactly. It is very cheap so you could try it, or maybe keep the stock spacebar (it doesn't need to shine through anyway) and use the rest of the keycaps from this set.
XVX Horizon PBT low profile keycaps: https://www.amazon.com/Low-Profile-Keycaps-117-Keys/dp/B0B49FLN6K