My opinion may not be welcome here, as I love OLD SCHOOL stuff.
If what you're after is a lightweight rocket, why not just hop-up a Honda Civic? If it was my truck, I'd put some vintage speed equipment on the 261, let that sweet 6-cylinder rap fill my ears, and grin from ear to ear, even while being passed by every import on the road.
Heck, my wife drives an old (2001) Chrysler 300M that almost meets your criteria, and gets 28mpg highway.
But, it's all about what you want to do. As 4t6 says, have fun and enjoy it, whatever you decide to do.
