Chris,
   Here are a few pix of my oil cooler project (still in progress).
http://neksiwel.20m.com/photo_1.html Click on  to enlarge.
Definitely use a thermostatic bypass. In the picture you will see the VDO
oil pressure sender, oil filter and hard plumbing. I will hook it up with
Aeroquip steel braided lines. The water-to-oil heat exchanger will stay.
Ken Lewis
http://neksiwel.20m.com/
in statu viae