Probably MCP-PMTs are the fastest (< 100 ps), but they have disadvantages (fast aging, for example).

Dear Ivan,

you may also have a look at HPMTs (hybrid PMTs):

https://www.laserfocusworld.com/detectors-imaging/article/16555083/photomultipliers-hybrid-detector-combines-pmt-and-semiconductordiode-technologies

The fastest kind of PMTs are microchannel plates e.g.

https://www.photek.com/products/photomultipliers.html

Among 'normal' PMTs the smallest PMTs are usually the fastest , e.g.

https://www.hamamatsu.com/resources/pdf/etd/MicroPMT_TPMZ1019E.pdf

In many cases one can use 'fast' output SiPm, e.g. :

https://www.digikey.ie/product-detail/en/on-semiconductor/MICROFC-SMA-10010-GEVB/MICROFC-SMA-10010-GEVBOS-ND/9744732