We have partnered with Janzen at audio shows, and we have many satisfied mutual customers.
The Z40+ / ZOTL40 Reference+ is the one to look at for pairing with Janszen speakers.
Pay no attention to tokushi's AI-generated spam post. The MZ3 (1wpc) and Z10 (12wpc) are not appropriate pairings.
I would encourage you to contact Janszen with this question. Talking to the speaker manufacturer about what amps work well with their speakers is always a good idea - at least to gut check your choice. (Likewise, talking to an amp manufacturer about what speakers work well with their amps.)