Ron-
considering the brakes, honestly, i would tell you look into someone like what I saw on a show, Muscle Car on the Spike Network. They were building a road race mustang, and used a set of spindles from Port City, nice big bearings, and rather stout looking pieces, and they were using screw in threaded AFCO ball joints. Bolted on the brake package from hell!
Granted, the control arms were completely custom built, but if you looked around, you could probably source a set of upper/lower control arms from the aftermarket and set the Torino frame up to work well.
I recently worked on a '69 Judge, and it had the Air Ride strong arm system, tubular upper/lower, and despite the slightly different mounting differances up top, I think a set of tubular uppers could be made to work.
One thing about the panhard rod-the full size mercury and lincolns had them on the 9" housings, I want to say 1975-1979 on the full frame stuff. I recall my '76 Gran Marquis coupe had a rod, which I was not expecting.
On the spring layout, if you can find someplace as you mentioned, that is great. The reason I brought up the spring cut spacer was by using a weld in cup you can still utilize a stock type or adjustable shock, but yet you can get 5" od springs from about any place such as eibach, or any number of the oval/dirt track places.
The truck arm conversion...keeps coming to mind.
For the money, if you were planning on running at speed, that would be the way to go. {something tells me Nascar can't be wrong on this one...}
One of my good friends has a 1974 Montego MX that will be going under the knife soon, for a complete David Pearson street driven clone, with plans for the Silver State classic...
One thing, on the rear arms, someone did a bearing conversion, and I have wanted to look a little more into this:

I have also heard for the mustang crowd of the same setup, with bearings for the strut rods, really trick pieces, for I want to say the 68-69 mustang?
I forget the site, but the strut rods I found looked like quite a well built piece.
I pulled up Speedway Motors catalog, and looking under their online offerngs, if one could utilize circle/oval track parts for the arms, you could have a number of options for suspension pieces.
Just depends on how far you want to go
Right now, for me, I'd just like to get my car painted.