Fluidyne triple pass with fans

Some of yall know I have the fluidyne with fans.... now when we put it in, we tapped onto the radiator acc fan....

Now that I think about it, the more stupid that is to me. Sooooo

Here is what I'm thinking.... fluidyne setup doesn't come with a thermostat/controller.

I'm thinking of going a different route.

Inline hose housing for a thermometer with a controller of some sort... do any of yall have any ideas? Or am I completly over thinking this

I found online 18mm outer.. 14mm inner.. inline housing with I believe a 3/8 threaded hole. (I need bigger for 10/12an) just example.

Thermometer/controller for 12v is where im not really finding something suitable(mainly temp probe portion)

Any ideas would be appreciated thanks