I run the series 2 and the t-case drop did not stop my vibes, it ended up a lot taller than 4" somewhere in the 5-5.5 range until I put all my body armor and bumpers on. Then it settled to about 4.5, but I have a soft top too. Yes you'll need longer brake lines, and unless you go sye and cv shaft, there's no way you'll be able to keep your spacers with just the t case drop.
If there's a will, usually there's a way, but then you get to that bolt that you still can't get to with two extensions, two universal sockets, and a contorsionist midget trying to help you.
1999 XJ Four door, mostly stock for now, but I am in the process of building a custom plate bumper.