So Many Rabbit Holes...

I'm in the exact same boat. '67 Barracuda, 400 4spd. I've been looking into exactly the same thing. Best deal I found is Cass at DrDiff. Front disc brakes with everything you need is about $800. $295 for new BBP rear axles with green bearings, add $60 - $120 for Precision or Timken bearing (respectively), plus $350 for new larger rear drums to work with the new axles. Totals about $1500 and then need to get new wheels and tires. He offers a new front suspension rebuild kit for a little over $300.

That being said,... he seems to be the most reasonable for the whole package and Cass gets great reviews. I have gotten a lot of stuff from him.