I was able to get a newer compressor, condenser and lines out of a later model Mopar at the the junk yard too. As long as you get all of the mating ends, you should be able to get it all hooked up. If you can gas weld, you can modify the ends to match what you already have. If you can't, there are companies out there that will make any end fitting that you need.
As far as needing different length hoses, there are some new hoses out on the market that only need heat from a heat gun to shrink the ends down and seal them. I'm starting to see then out in sales catalogs.
I ended up finding most of the A/C stuff on the ground at last year's Mopar Nats, so I didn't need the newer stuff.