It sunds like you m ight have some bearings or oil pump problems. Have you hit anything that could have damaged your oil pan? The distantce between the oil pan bottom and the pickup is critical as it can get too close and keep oil form geting to the top end of the engine and other bearings. If you are hearing a squaling sound like you said your power steering made then you might have turned a main bearing. I hate to tel you but you could be looking at an engine rebuild. If it is stallling and squealing with low oil pressure than there is some reason that is keeeping the bearings from allowing the crank to turn easily or freely. The term, "Spun Bearing" frefers to when oil pressure gets lows enough that the bearing makes contact with the crank bearings and will squeal and cause low oil pressure. If this is happening at idle and when you start it it is probably not goood news. However it is hard to say without beeing there to hear and see what exactly is happeninging. It might not be so bad if you have not damaged the oil pan. Give me some more information and I will walk you though it.

Well one mechanic says it may just be my air conditioning pump? Then possibly a couple bearings as well. My oil pan is not damaged. I was told it'd be about 700 to get the pump and bearings fixed, does that sound about right? I really would hate to lose this durango cause its in great condition.

That is not a bad price for the pump and the bearings should be in the pump so I don't know what they mean by that. The one thing that will have to be done is to recharge the system with R-134 refigerant and check it for leaks and that is worth $100, the new pump is around $350 or more, then labor is around $250 or more. So that comes to $750.00. So, you are getting a good price.
I am glad to hear it is not the engine bearings because that would have cost thousands.