The Blackwings, Porsche 911 and 718, Civic Type R/Integra Type S, FRS/BRZ twins, Emira, and of course the Miata, all represent the pinnacle of driving enjoyment and they can still be had with a manual.
I stopped reading C/D and R&T and so I'm not current on the new cars. This is the first I've heard of the Emira, and that looks pretty darn good! Wow. I'd be tempted, just on looks. I'd also be hesitant, because English car.
As to the OP's original question, as previous owner of earlier generations of the Boxster and Z06, both properly equipped with three pedals, as well as a previous and current owner (wife's) of PDK cars, my thoughts:
- Every boy (and girl) should own a Porsche sports car at some point.
- If you can, you should get the manual transmission, although as noted above, the 7-speed isn't that great.
- The Boxster/Cayman platform is better than the 911 if you want to drive. If you're cruising, get the 911.
- If you are not going to track it, a GT4 is overkill. You could almost say the same about the GTS, but if it (here I have not kept up with Porsche models) comes with the flat six instead of the four, then it's probably worth the upcharge.
- I remember I once bought a big touring bike so that the wife could ride with me. She rode with me
once. Buy it for you, not her. Be realistic about how often she's really going to use it.
- The PDK has some real positives, but there are negatives as well. It can get confused and not perform as expected, the low speed/maneuvering behavior can be, let's say "unusual", and God help you if something goes wrong in there out of warranty. And it will affect resale negatively.
- The C8 is really unsurpassed for performance/cost, but it's still a plastic Chevy, and I think it's ugly, it's difficult to get in and out of (although the Cayman can have its challenges as well) and I think resale will be miserable now that the bloom is off the rose for the Z06.