Perro,
Why limit your choise to 4/4 and roadster? I went for the Plus-4. I dont regret it. With 145 bhp it is a fun car to drive. I normally do 85 to 90 on the motorway but it cruises equally happy at 100+ mph. Dont know how fast it will go yet but motorway use is not a problem. Driving on the smaller roads is a blast. If you keep it on the boil a bit it is very fast. Maybe not as relaxed as the roadster, more gearchanges required probably, but big smiles and last but not least, I have averaged 38 mpg so far. Go test drive is the best advice.
Good luck, JT