Hello gentleman!
I found an interesting product it is ISE30 from SMC. Perhaps that will give ideas to some among us. It is an electronic Hystereschalter and Druckschalter all in one. Small, this size is 30X30mm.
The price in France is around 75 euro. It is approximately the price for Hystereschalter and Druckschalter together.
Here the link:
http://www.smceu.com/Prod/DE/Contents/P ... -ise30.pdf
Bye
Alexandre