Lowering leaf springs

This is the setup on the car now:
Slant6, small cam, dual 1 barrel carbs,dual exhaust
Disc brake conversion sbp 11" rotors
Stock torsion bars
Tires 205 65 r 15 front/ 215 70 r 15 rear all new rims and tires
Kyb shocks all around
S/S springs
7 1/4 rear 9" drums
Trying to setup as a good handling daily driver
Future setup :
Rebuild front end
Full poly kit all around
Adjustable strut rods
Off set caster bushing
Sway bar kit( front and rear or just front?)
Borgeson power steering kit
New leaf springs
10" rear drums if possible
Will the 11" rotors and 9" drums sbp setup will this be enough stopping power . Trying not to convert bbp setup.
Any help with name brands on parts will help. Also changes on future setup that would work better. Thanks