Hi welcome to the world of the CC - when you get one!!
You have probably chosen quite a good time to buy a convertable as they tend to go down in price as the winter comes along and people (wrongly) think that they will be nasty horrible cold things.
The beauty of the CC is that its a hard top in the winter and a convertible the rest of the time, I insist on the roof going down whenever I drive ours, unless its raining hard
AS Lyndon says make sure you geta warranty or such a good deal you can afford to buy an aftermarket warranty that will cover the electrics and exhaust.
Go for the 2.0 SE with leather they go really well.
Are you buying a new one or a second hand one?? If its a new one then consider buying an import with a 2 year warranty, they are really cheap in comparison with a dealers car and some places will give you a trade in (trade sales, slough for example)
If its a second hand one then make sure you test everything, 206 electrics seem to be fickle some cars are no problem, others seem to have loads.... if the roof works, the lights stereo,heater, wipers washers and indicators central locking etc also work then there is every chance its a good one... if any of it doesnt when you first inspect it then walk away, coz chances are it will never be fixed to your satisfaction!!
Good luck with your search let us know how it goes