This is screaming out for for the exact opposite of a Boxster or Mustang. You want a flashy looking coupe with enough poke to not be out done by the local yobs in their 1.4 Corsas.
Basically something like a VW Scirocco, BMW 120i/320i Coupe or an Audi TT.
Completely avoid anything like a Boxster, 350Z, Honda S2000 and any other standard OcUK favourite because you simply do not want to spend the extra money running a quick car.
The Scirocco, BMW or TT in standard petrol form (all with roughly 150bhp) are perfect for what they are designed for.
They are a brand new iPhone or a nice new Superdry jacket and that's exactly what you want - looks good, functional, flashy, and reasonable well built.