i would also like to know about the pressure senders
tried the one that came with a racetech oil pressure gauge and its way out

for thermocouple, like gareth says any k-type will do, the one i has comes with a long lead on and the correct plug, i read that normal copper wire cannot be used for an extension or accuracy suffers

but there are 2 pots inside the monitor on a seperate board for the thermocouple, i guess for upper and lower calibration points?

compared my reading to a standalone k-type thermometer and it was accurate