I have the 4 leaf springs new last year, and I like them. I debated the same issue, and ultimately I was glad I chose the 4 leaf route. I think you will not like the stiff ride from the 5 leaf version. The four leaf has the correct ride height, and I feel it is very tight on the road. New shocks also helped this.

You might prefer the 5 leafs if you are running ladder bars and 12" Mickey Thompson drag tires.