360, LA360, or Magnum 360?

I really hate to ask questions that show my ignorance...but

If I was to swap out my engine for a 360, which one should I be looking for? I just read that the magnum 360 will require a $800 intake manifold. 'Course It does have the roller cam

I think I'm correct that the early engines are the LA series? Not sure what year they went to the non LA

Could I get a little advice here?!! This is my first Mopar! And admittedly I'm not a gear head... Wish I wuz though! I'm learning a lot here on this most awesome site.

Anyway I realize that the 360 will pRetty much drop in... Needs balanced different... Needs a different oil pan... And the magnum needs a $800 intake manifold and possibly an electric fuel pump or a different cam.

I guess I'm thinking - not doing the magnum... More $$$$ than I want to spend. I am happy with the performance of my 318. It is just getting tired, low oil pressure. So looking like a LA360 or the later 360. What donor vehicle should I be looking for? And what year?

If I go with the LA or the later 360, do I still need much modifications, other than externally balance and a car oil pan?

THANKYOU AGAIN!

Mark