new project suspension

[jaydex]

Looking for suspension suggestions on a new project. I have a 67 2wd short box fleet side with factory leaf springs. Looking to run about 550hp through a 6.2 Ls I have. My question is the suspension. Truck will not be driven to hard (mostly).
Thinking a modest drop of about 3inch to 5inch in front 4inch to 6inch in back. I have a 72 frame that has the disc brakes so I was thinking switching the front clip and just going with lowered spindles and coils? Or buying a whole new set up? In the back I could just do a lowered spring and a shackle to get the height but not sure how that would handle the power. Not really interested in airbags. I see a couple places sell a bolt in Tourque arm suspension? This truck will be driven by wife lots not going to be hitting the track.