Do you want really good functional brakes, or classic aura brakes? If you want good performance (tires and wheels too), then forget about SBP rims and hubs. What is your budget for the whole brake and susp setup?
You can make the KH setup work well but they are finicky and reman calipers often leak. I had a set on my 68 Dart for several years and went through a few reman calipers before I got a pair that did not leak. Yes, they were warrantied, but I had to keep swapping the dern things. Also, I did not like the pad options and they did not give a good pedal feel.
If it were me, I'd get 73-76 A-body spindles and UCAs and build brakes from there. 11.75" rotors are much better and work well with Wilwood dynalite calipers. Here is what I did on mine, but I'm not sure you can get those adapters anymore.
http://arengineering.com/tech/mopar-mus ... e-upgrade/
Man, there is a lot less out there that is not bling'ed up these days. Need to contemplate this further...
Tim Herren has a kit, but it is a bit of cash. It should work really well...
http://alltimeracing.com/product/product-one/
If you want simple and not expensive, and do not care about weight, then call Doctordiff(.com) and get one of his kits with all included.
http://www.doctordiff.com/brakes/complete-kits/
I would get the stage 3 myself...
Hope this helps,
Lou