Nonono to the hangers!
PitA to install, & they'll mess with your pinion angle.
Go flip kit & move the spring down to the other hole on the shackle. That'll give you 7" of drop.
The flip kit has the pinion angle built into it, but due to the use of the shackle for that additional 1", a small (1.5*) pinion wedge (maybe/probably) will have to be used to correct that.
When that wedge is used, the leaf-spring centering pin will have to be extended.
GM lists 4 different lengths of those. Cheap! Get the next longer one, crank a nut down tight to the head, then round off the knuckles on the nut to the head's size.
Front = springs & spindles for a 4" drop.
The truck will sit level, no tilt, with that 3" diff front to rear when @ 4/7.
Gotta notch the bed crossmember over the diff. pumpkin.
E-brake lines will have to be moved around a bit so they don't get pinched anywhere when the suspension compresses.
The bracket for the rear hydro line & the 'T' union on the top of the pumpkin will also need to be slightly repositioned.
If your an easy-going cruising type of driver, the Doetsch shocks (nitro-drops, nitro slammers, whatever) will be fine.
More of a 'performance' oriented driver? Spend the few extra bucks & get the BellTech Street Performers.
Don't know the mileage on your truck, but I'd recommend new bushings for the control arms, leaf spring eyes, sway bar mounts & body mounts. New rubber ones will be better than the original stuff in there now. I like the urethane bushings, but they do stiffen up the ride somewhat. If you decide on the urethane, buy a complete kit. Few more bucks than purchasing the rubber ones individually, but not a whole lot more when buying as a kit.
The urethane control arm bushings are a bear to install. Need a hydro-press. A big one! Keep the original outer bushing shells when removing the old bushings. They'll need to be re-used. No-one sells/makes them, other than maybe GM or the wreckers.