The Ariel Atom is an awesome vehicle, one of the guys I race with has one. Unfortunately it is loud, uncomfortable in the summer and winter, and totally impractical. Basically it's a road legal track car.
If you have the ability to get it to the track on a regular basis then absolutely go for it. If you're not going to the track then you will hate it in 3 months and want to sell it due to its total impracticality.
... er Euros.