Don't use a relay for the probe as you'll get a delay and you don't want that.

Regards the relay then just use a Standard 12 or 24V relay for the limits. Unless your BOB inputs can accept 24V which they won't All your doing is running the 5V signal from BOB thru the NO contacts and keeping the wire length to the shortest possible. Most false trips are picked up from the Long limit switch wire runs connected directly to the input and often close to power cables acting as antena picking up stray signals. Using 24V means you can run it thru the Limits and E-stop to power the Relay coil making the system stable and won't trip the relay unless broken and keep the Signal wires short and inside the Control box.

Also I wouldn't use Solid state Relays as they tend to fail On which is BAD news for limits.!!