Like comparing apples and oranges this! 2 totally different cars, zed is a cruiser/bruiser with plenty power, s2k is more agile/nimble and a convertible that you need to drive hard to have fun in!
350z and BMW are definitely more GT cruiser than lightweight sports cars. My vote would be a well sorted mx5 or mr2 mk3 as a daily. And as above, maybe a 350 project for weekends if you can run them both.