Those contacts are normally custom built. The biggest thing with them is how the ends are setup to connect to the electronics. There are, as another mentioned, "pogo" pins which are used in the hot testers for electronic assemblies to make contact with locations on PCB assy. and they aren't too expensive. The other thing is to get the spring side contacts made up from stamping phosphor bronze and getting it gold plated and the other side of the contact is a pad on a PCB that is usually gold plated also. Tin plate will work but the resistance is higher and you may have more troubles with corrosion and dirt.
-- Why isn't there an Ozone Hole at the NORTH Pole?