My thoughts on the budget boost are not to waste the money if you plan to go higher at some point.
I was too lazy to click the link, but for $500 (and I paid way too much for some stuff cuz I was too lazy to look for cheaper), my lift was made from:
front
ZJ coils (later replaced with 3.5 Rubicon Express coils)
1.75" Daystar spacers
stock spring insulators
spring insulators from a Camaro
rear
Dakota leafs (used the main leaf from the XJ and ALL the Dakota leafs, including the helper)
Ford Ranger shackles
new u-bolts and and spring clamps from O'Reillys
This netted me 6" of lift and I actually like the ride. I have no idea how it flexes because no one ever seems to get pics of my Heep.
For the front brake lines I just unbolted and straightened the steel line (yes Kurt, I know they still need to be remounted)
For the rear lines the same thing (only because I have yet to get a bolt loosened to replace the line with the longer Dakota one).
You can also use GM front lines to increase the length.
Everything bolts right in and is an easy lift to do.
I am lucky in that I have an older XJ so I was able to do that much lift without much drive line issues (well, except for causing my front shaft to snap, but that has more to do with the fact that it was a CV shaft than anything). You will probably need to drop your transfer case an inch or get a slip yoke eliminator.