Its really easy to fab up your own brackets for the front. just lay a flat plate across the lower arm, and trace the shape of the control arm onto the metal. drill some holes through the plate and arm, and bolt them together. For the upper, fully compress the lower arm, and measure from the top of the spring pocket to the plate. Subtract the height of the collapsed bag from the measurement, and cut a length of 4-5 inch pipe. weld it to a flat plate, pop some holes, and there ya go.]
For the back, leafs really suck... you may need to mono leaf it, and fab some mounts and a bridge.
Compressors, just look for anything with a 100% duty cycle, an at least 3/4 HP. Blowjax makes a nice unit. Alotta people like ViAir, but their CFM is just too low for my preferences..
Check out
http://www.lowriderimpala.com for some install pics on a 64 Impala, I show some decent pics of the brackets I fabbed...
good luck, and be sure to hit us up with some pics of your Holden!
You should be able to resize them with various programs..