Get one from a main dealer with a 12 month warranty for peace of mind. I've had mine for six months or so and it's certainly had problems. The dealer has been pretty good and half the car is now brand new so I'm fairly confident that I've had a goody. If it didn't have the main dealer warranty then the car would have been long gone by now, so I'd agree with you on the warranty point. It's worth the extra.
There's no doubt that there's something special about Alfa's mind. Mine has spent most of my time with it ruining my life but I still love it, and as I said, I now think that its in pretty good nick and I've still got a lot of warranty left so I'm not too worried.