Lowering leaf springs

I'll look into proforged parts. As far as leaf springs should I stick with shackles or look into rear sliders?

I think you’ll be fine with shackles. Sliders are a pretty minor improvement. Again, if you were racing or competing they might be something to look into. I do have them on my Duster, just another step in optimizing the suspension, removing binding and flex. But they’re a really minor change compared to the work needed to install them, I can’t say I noticed any big difference in handling after I installed them.