from your choices id say get the new car if you can afford it. i just always like knowing every thing thats happened to it, how it was driven, ect. granted my stang was used there were some things i wish the previous owner had not done/taken better care of. but even over that id say test drive all your choices and pick the one you like best overall. and ever in auto i dont think getting your stang to match the speed of your hemi will be much of a challenge
That's like me saying ...."Trust me, eating an apple can't even begin to compare to eating an orange". It's a matter of what you prefer. You say you've had an auto with shift kit, gears, and "all that stuff", so I'm not sure if you've ever had an auto with a good converter, but it makes a BIG difference in performance and the fun factor. But that's not going to convince someone who prefers manual shifting to switch to an auto. I've driven both types, and I'd be miserable with a manual trans driving in the city every day.