Coyote V8's, though - now you're talking!
Honestly, I'd only go with an 11-14 if you absolutely had to have a live rear axle. The S550 is such a massive improvement in every other way, including the strength of the stock engine, that for a daily-driven Girlfriend-friendly hotrod I'd take the S550 and never look back.
For an SC, Whipple is the way to go. Fantastic kit that is easy to install and they've got very good tuning packages to match their product. Having worked on hundreds of cars with aftermarket superchargers, I'd only go with a centrifugal on a Corvette or similar car that made a twin screw impossible for some kind of packaging reason, and Whipple makes by far my favorite and most trouble-free twin screw design in my experience.
I'd also avoid thinking in terms of boost pressure. Boost pressure is relative to the compressor involved so comparing 10psi on a Vortech V1 vs 10 psi on a Whipple AX175 vs 10 psi on a Borg Warner 9180 EFR turbo are all substantially different things and while they'll make somewhat similar hp, it would be folly to assume that boost pressure is commensurate with engine abuse or overall HP level. A properly tuned 11-12psi is 1000 times safer and less dangerous AND more powerful than 6psi on a shit tune.
But yes, Coyote plus Whipple is a good time! Coyote plus an Armageddon Turbo setup is even better, especially with a built engine, but that gets spendy quick.
Also, Hellcats are overrated. They make the HP advertised but they're such big ass sluggish boats that the ~640whp they make stock feels like a ~525whp Mustang or Vette. Which isn't any kind of slouch, but I'd much prefer a ~675whp Whipple'd S550 Mustang or ECS Novi 1200 equipped Z06.