Several companies sell the basic swap kit, with just the necessary bracket and hardware. The calipers that are used most often come off of a 78-81(84?later?) GM midsize, like a camaro, or monte. those years usually have the smaller "metric" caliper.
The earlier 69-77 GM midsize car caliper is larger, with a bigger piston, mounting hole spacing and pad..
Scarebird is another good place to find a bracket/ hardware set.
my signature lines...not really directed at anyone in particular..
BE different....ACT normal.
No one is completely useless..They can always be used as a bad example