Do yourself a huge favour
Get yourself a Toyota Starlet GT Turbo
Why??
Because they are only a 1.3 engine and some insurers class them as a group 10 but heres the beauty of them, they have more torque than a Porsche 911 size / weight ratio, standard they do 0-60 in 6.1 secs, with a few minor mods, dump valve / hks filter 5.5 secs or less.
Not only that, they come fully loaded as standard, aircon all electrics etc, in the 11 years i have driven these none have ever gone wrong, even after severe abuse, unlike my Skyline ( �4000 bill in last 2 months)
Add to that if you drive sensibly you really can get up to 40mpg if you dont get bored by then... Tax is only �110 yearly, and heres the best bit you can buy for as little as �1000, for someone your age its a no brainer