you can go up to 5" without relocating the brake lines. just don't ever leave the paved road.
2"= no relocating required, but might still recommend
3"= relocate stock lines down aprox. 1.5". recommend longer lines with future upgrades in mind.
4"+= get longer lines.
as far as "easy" install. well all lift kits pretty much replace the same components, so they're all the same. one way to make the initial lift easier is not to replace the full leaf pack, but to install a full length add-a-leaf. that way you don't have to remove the bolts from the spring eyes. that's pretty much the worst part of XJ lifts.
extending your brake lines isn't a big deal, your lifting your car and worried about something that will be the easiest thing to do, i nvr extended my fronts but the rear was being stretched so i added a rubber brake hose onto the metal line and cut and reflared the shortest correct size brake like murrays sold to be like 3" or less and used that to connect the brake hoses, if you need a pic, pm me
btw, personally if you can scrounge the money together or have it or whatever, it would be best to by new leaf packs, aal since they're 1 sometimes 2 leafs giving you like 3" they stiffen up the leaf packs and give you a stiff ride that is 3" or less.
as my buddy said to me, "you wouldn't use a band aid if you cut your arm off, would you?"