Where can I find Coil springs and shocks for 12" plus lift?

Im planning on building a both front and rear 4 link pickup 4x4... but I cannot seem to find coil springs for a 1 foot plus lift... I am not sure how high I want to go and I do know how big lifts affect steering so please dont answer as that... I just would like to know where I can find springs and shocks... All the sky jacker products I find dont say how long the springs are. Thanks! I dont care what the springs are for as I will be making my own brackets to hold them...or robbing some off something...