Easiest to install on stock spindles would be oversized piston calipers. While aluminum calipers do weigh less they also flex more than cast iron calipers, its a trade off.
I went with the USBrake,now AFCO,oversize metric calipers several years ago.
With those I bought a pair of Summit Racing slotted and cross drilled rotors and Hawk HPS pads.I also put a set of Russell braided brake lines on at the same time.
This combo works great for me,I've never had and issues bringing my 650 HP BBC to a stop.
Here is a link to my brake upgrade project;
Upgrading G Body Front Brakes
This is how I upgraded the front brakes on my big block powered 1986 Monte Carlo SS without breaking the bank.At the same time,I also added ...
gbodybudgetfrontbrakeupgrade.blogspot.com