Do I have a faulty crankshaft position sensor?

I have been having an issue with my Durango that I have never experienced with any other vehicle that I've owned. It has several symptoms that mya or may not be realted to the same thing. The biggest issue I have is the Durango will just shut off driving down the road doing approximately 50 mph. No warning, no check engine light, no sputtering, just all of the sudden there is no power from the engine. Everything electrical still works when this happens (radio, headlights etc.) The second symptom which I believe is directly realted is the the Durango just shuts off randomly at complete stops. This issue is prevented if the transmission is switched to the neutral postion and the brake is applied and the engine is revved up to 1000 rpm or more. The third symptom is when trying to accelerate heavily (merging onto a highway for example) the engine will rev up but the entire veihicle will jump and shake until the accelerator is released and then pressed slowly to gain speed. The fourth and final symptom is the vehicle will not start in quick situations (i.E. Running into the post office or gas station where the engine is only off for a short period of time). The engine cranks and tries to start but just will not turn over. Shifting to neutral and trying to start the engine with the transmission in neutral usually gets it to start on the first try. The oil level and oil pressure checks out ok, there is no vaccuum leak that I can find, fuel pressure and delivery seems to be ok, and the most frustrating thing is no check engine light comes on and no trouble codes are displayed (incl. The "no bus" display that some people have when the pcm fails). Without the trouble codes or check engine light I havent able to get any real guidance on waht the issue can be. I believe I have narrowed the issue down to four things: crankshaft position sensor, camshaft position sensor, neutral safety or ignition sensor. A diagnostic test will cost me more than it would to purchase all of these parts and replace them myself. That being said I dont want to buy all of them when only one needs replacing. Any advice on how to narrow down the cause of these issues and select which part to purchase would be greatly appreciated