For the parking brake, just separate the cables in the middle of the truck. After you look at it, you will see what I mean. Then after you attach the drop bracket from the kit, re-attach it.
On a 2nd gen, There are 4 drop brackets for the radiator. 2 rectangle, and 2 tabs. Tabs on top, rectangles on bottom. An easy way to rectify the shroud is to cut it in half (across) and attach both halves to the stock locations. On a 1st gen, there are 2 flat drop brackets on top, and you install a single bracket to the core support in the middle attached to the shroud.
I would definitely run a steering ext for a 3" body lift. You can make your own if your a good welder/fabricator. They are available to purchase individually.
They are expensive being a completely machined part.
http://www.summitracing.com/parts/PRA-SE3500/
I wouldn't worry about the shifter extension at all, but if you have to have it....
http://www.my4by.com/body-lift-manu....html?osCsid=0f19b1523f9332113c9199e5990e52ae
Just make sure you remove the connector for the shift cable on the firewall, unplug the harness for the Transfercase/trans, all the ground straps on body mounts and firewall. Only do 1 side at a time so the body don't get separated from the frame and falls off.
Use 2x4 lumber to fit in the body cavities (in center of rig) on top of your floor jacks to lift for puck placement. Best to have another person when doing this job for safety reasons.