Auto bed level sensor on Ultimaker original

[Ca3PO4 2]

Hi , iv got an Ultimaker original with self built heated bed upgrade, got glass ontop of the heated bed and I would like to add an auto bed level sensor the question is what kind of sensor to get , theres a shop in my town they got an optical and induction , which one is better? Does adding such a sensor guarantee that the bed will always remain level ?

The second question is how do i connect the wiring to my ultimaker original main board, I mean would i just replace the z endtop connection with the new sensor or do I have to connect it else where ? are there any printable mounts for the sensor if so please please share

Thanks for your time. Looking foreward to a reply.