I have the
HD Premium oil cooler kit on my Ultra (PN 26155-07) as well as the oil temperature gauge - fairing mount (PN 75324-05) to replace the useless (IMHO) air temperature gauge with something worth having. My temp runs around 180° - 200° when I am cruising. The cooler has a built in thermostat that bypasses the cooler when the oil is cold so it warms up normally.
Part number for a cooler for your steed would be 26151-07 and comes with a nice chrome cover that looks really nice. MSRP for the cooler is $299.95.
That LCD dipstick (PN 63004-09) is pretty cool looking but I darn-near dropped it at the
HD shop the other day when I flipped the box over and looked at the tag. The one for the 07+ touring bikes are $139.95!
I've had oil coolers on 3 of the 4 Harleys I've owned. I think they keep the motor cooler in the summer when the free air temp (here in Florida) hits 90°+
and you are rolling. Sitting still in traffic, they don't do squat.