Good luck. Whatever decision you make, you end up with an awesome ride.
BTW that wing is functional and adds a measurable amount of downforce at speed.
Problem with the Z and warranty, if you want the speed of the Supra your warranty is pretty much nill. The Supra was way over engineered and is very reliable, of course with age and miles will always become issues, but this is not a FD RX7..
I'm in the same boat with you and the NSX. Sometime you just need to live that childhood dream
One thing I will say is I missed the refinement of the Supra when I had the 350. IMO the 370 is on par, aside from the coarseness of the engine. Given the cost of the Supra when it was new (mine had a sticker of over 50k) I still worship Nissan for putting together such an awesome car at a great price.
On the My Z site, in the other vehicles section someone just picked up a 98 in the low to mid 30s with under 30k miles IIRC. Killer deal.
Keep us updated, I am excited! I would def spend some time with that targa off, it lets just the right amount of air in, and really adds to the driving experience!