I have been doing some research and it looks like I will be going with a 4/6 drop on my truck. My goal is to get it more lower than it is now (currently has a 2/3 drop I think) and LEVELED. When I bought it the guy told me he had a kit on it already but it has a stock look and I want to change it up, plus he told me he put new shocks on it.
Now my questions are
Will I need to purchase new shocks since I will be lowering it more?
If I go 4/6 will my truck bottom out (I have dual exhaust on the truck)?
Will I need to do any configurations on my truck when I put this kit on?
Will I lose my smooth driving I currently have on the truck (dont want to bounce all over the place etc.)? Note: I am planning on getting the right kit not a chop shop kit

This is the site I am thinking about getting them from. Its the last listing so scroll down once you are on the site.
http://www.gmcpauls.com/73-91_d&s.htm
Also if there is anything else you want to add that would help me out here. I am planning on getting new tires and rims as well. But my man at Perry Bros told me to get it dropped first before I purchase so.
Thanks in advance.