I too am with Dusty. It all boils down to what mods you plan on doing. "PLAN AHEAD", have a game plan in your mind "even better on paper" of how you want your end results to be.
Stage 2 shocks mounts require a BL
Large 24 gal gas tank, BL is great to be able to get more ground clearance
What about tranny, A BL is sure nice if your going to stuff a big ZF under there.
Power plant, BL is sure sweet if you are planning on stuffing a 351 under the hood or even modifying the 302 with a performance intake and 4B carb. Sure you can buy a scoop or even another hood but the extra room is sure nice.
Washing the mud of your rig, BL is priceless, allows to get to the top side of your running gear really well.
BL also helps with your center of gravity, this helps with body roll as well.
The frame on these Broncos are stuffed way up under the rig and even with a body lift its hard to tell from the side view. The front and rear are most noticeable and can be fixed by filling the gap in with some angle iron or square tubing or installing aftermarket bumpers built to accommodate the BL.
Either way will work so it still all boils down to what you are planning to do to your project. good luck.
;D