I work with Steve Mitchell quite a bit and what you propose in the rear is exactly how his car is set up, a G37 rear subframe with SPL links.
For my personal 350Z time attack car if it ever gets worked on, I plan on relocating the longer stock links to reduce antisquat and to have less of a toe-in curve and to run slightly more static toe in. I think this might have a more linear feel to how the rear responds. It ends up being about 12 lbs lighter this way as well due to the aluminum subframe. I think for this car I am going to ask Eric Hsu to team with me, he handles the powertrain development and I do the chassis with Steve and John McNulty handling the aero. This would be the low buck tuners dream team.
Steve and I have both looked at the 370Z knuckle and hubs and there is no easy way its gonna work. Our latest thinking is to go to a die maker, anneal and weld the hell out of the hub to build up material, then solution heat treat it and remachine it for the larger hubs. Whew. It still won't be as beefy as what the 370Z has though.