Leaf springs and what to buy!

So, I'm buying new leaf springs for my 68 dodge dart, I was gonna buy the SS springs 2 passenger from summit, with shipping they come out to like a total of $235 for both. Now I had some 8" shackles or hangers (dont know which) when I bought the car. So I need to know what to buy, aside from the springs haha

Difference between hangers and shackles? I take it shackles are the extension?

I take it I need to buy new hangers? or are the ones I have now good I just need new bushings? Im gonna need new ubolts as well, had to cut the old ones off, too much rust.

Thanks.