As mentioned above, go with a 9" and be done with it. A Ladder bar coil over rear suspension would be my choice as well. Up front, I'd recommend a cross member swap that will utilize mustang II suspension and coil overs. This fella builds them and you can weld one in place of the original.
https://welderseries.company.site/
It's also possible to substitute a bolt in front subframe from someone like Smith Racecraft, Detroit Speed, Chris Alston, etc, for an early 63-67 Chevy II.
Lastly, if you're on facebook, there's a fella by the name of "Dean Rock" do a search on him as he's got a sweet 62 Tempest. Cool and very talented guy and will advise you on how he did his car so you can emulate his build.
I'm curious to how much power you plan on putting in the car with the BBC?