Help decide which lift kit

[XChris1632X]

I am looking to buy a new lift kit for my truck. Right now it is 4.5 inch skyjacker basic lift kit. I swore I would never go with a skyjacker kit again but while shopping for a new lift I realized they are the only company to offer all the little things I want. The biggest thing is that I want a new spring pack instead of an add a leaf. My springs are wore out and add a leafs ride like dump trucks. I was going to go bigger but I decided to stay with 4.5 inch lift but I think I want to upgrade from the basic kit to the Dual Flex kit or the Coil over kit. The Dual flex is about $2600 and the Coil over is right around $3200. What are the benifits to going to a coil over kit? I figure if it is worth it I would spend the extra $600. The lift that is on it now is about $1200 so I am hoping there is a difference in quality between the two. My lift now has suffered wear badly. I think the winter is to credit for a lot of it, so my truck will never touch winter weather again after it is painted. Just looking for some opinions.