Billies and leaf question

Need some advice. First, why is the all pro 3" leafs cheaper than the ome Dakar 2.75?
And second, just ordered my 5100's and will order my spindles in 2 weeks. Should I pit the front billies at .85 with a 2.75" or 3" leaf or should I set it at 1" with a 2.75" or 3" leaf?
I want it to ride level and smooth and if at worst, withthe back end a little higher.

 

Assuming they are 4" spindles, you'll need the 3" leaf pack just to be level with billys at zero.

 

Camburg recommends a 2" leaf or block with the spindles tho?

 

Bro lean.

Stock rake is about an inch.