Needless to say, you've picqued my curiosity. Why would you be interested in oil temperature (what do you think it would tell you), and where on the oil flow path would you like to measure it? Generally, the temperature of the coolant in the block and the oil pressure are much superior indicators of engine status, so it intrigues me that you would want to monitor the oil temperature.
Engine oil temperature on this (and any other) motor is an interesting proposition. Obviously, it will vary greatly depending on where the sending unit/sensor is located. An easy location would be to tap into the oil pan or the oil cooler lines that run from the filter mount to the cooler in front of the radiator. You could cut either line and use a T with a flare or pressure fitting. While fairly simple, the temp would vary depending on if you used the supply or return line from the cooler, and even that would vary with ambient temperature. I can't think of anywhere else that would be convenient to tap into the block other than the pan itself.
Perhaps I could suggest two other alternate items to monitor that would be of greater value to you on this motor. The first is EGT (exhaust gas temp), which can be measured with a pyrometer gauge. There is already a hook up on the exhaust discharge of the turbo for it, and it would tell you a great deal about how your motor is performing. The second is turbo boost pressure. There are kits that mount these and other gauges on the driver's side A-pillar that look factory installed.
Good luck - Jonathan