Thank you sir! Since you already have the isolator/heat sink, you can go through ebay or amazon.com - search 6.5 PMD and you will see a plethora of options. Both places seem to be around the $200 range for new ones. Only benefit I see with ebay is that some vendors have a package deal with a resistor (that must be present). I recommend a #9.
Check out Heath Diesel, Inc. »
, they have a lot of cool goodies there. I got a lot of help from a very knowlegable guy named Bill, and their products turned my old 95 Chevy into a new animal. ssdieselsupply.com is another vendor with lots of goodies. I really like to see those 6.5s on the road, it's not very often. I miss my old truck, just needed - ok, wanted something bigger.
BTW, That turbomaster from heathdiesel is a worthy investment. The vacuum pump on the truck operates the wastegate for the turbo, and they are known to go out. Fortunately, the 2500s have the L65 engine, so thats the only thing the vacuum pump operates. The brakes are assisted by the power steering pump. If you get the turbomaster, you can actually do away with the vacuum pump completely - just get a shorter belt from your local auto parts place. One less accessory for the engine to spin for no reason - if it's bad of course. One way to test the vacuum pump is to start the truck, open the hood, grab the wastegate rod and try to move it. If you can move it, the pump is bad.
Any other questions, let me know - I'm happy to help, if I can. I've done much research on those engines, just don't have the truck to use it on!