I would take a look at the Continental Extreme ContactDW as well, they are more expensive but are supposed to be a great tire. The Hankooks are a good tire for the money as well, but you probably aren't going to get a lot of miles out of them. You got a lot of miles on the Pirellis, so I would guess you would get something like 30-35k miles on the Hankooks. I would avoid the Maxxis tire I think, never heard of anyone using them. The Cooper is going to last a long time, but as you suspected, will probably have pretty low grip.
Really? You got about 8k or so more then I got from mine and I have 100 less ponies under the hood then you!!. Seriously though based on my own experience and what I have read here and on other Mustang sites most P-Zero summers only last around 12-16k and the seems to be the case with most ultra-high performance summer tires. Of the three tires you posted I have never heard of Maxxis and know nothing about them. They are so much cheaper then other brands in that size that I would have serious concerns about their quality. I have Hankook V-12s on my car. I am happy with them and notice no difference in performance compared to the stock Pirelli's. Like ct07gt said the Coopers will probably hold up the best but handling and brake performance will suffer.
I thought you had the summer PZero, but if you had a TW rating of 400 then they are probably the PZero Nero All Seasons. I would have thought you would have gotten more mileage out of those tires than that. I don't think you are going get a lot of life out of the Hankook V12s, I had the Nitto Invo with a 220 rating and got 20k miles out of them, some of it was autocross though, and my current Dunlops with a 200 rating will be lucky to make 15k miles. You have to decide what is the biggest priority for you, cost vs grip vs treadlife.
Oh sorry then... in that case. What the hell are you doing to that poor car that you are only getting 24 k out of those tires !?! Maniac!!
Just kidding of course. If your main concern is thread life then I would avoid the Hankooks since they will wear faster the the PZeros , and go with the Coopers.