Only one I've found is PedalPCBs, but I'm not 100% where he got it from, so I'm 50/50. I do know it's a modified Zendrive, so not much you can really change/add:
https://www.pedalpcb.com/docs/PhoenixUltra.pdfI built a Zendrive & Ultra Phonix into the same enclosure and got them to sound exactly the same. I'd build a Zendrive since you can tweak the sound more with the Voice control (Ultra Phonix just has a fixed voice "control"/resistor)