I put two different monovalve rebuild kits into my car. Both were the MTC brand since OEM is either hard to find or way pricey. I found the klima design works kit online and put it in. I was seriously happy with it.

https://www.klimakit.com/product/monovalve-and-coolant-circulator-pump-eliminator-upgrade-kit/

* I am not affiliated with this company. Just surprised I haven't seen it or something similar on the forums much.