Re: alfa gtv 6
Not sure about 'Classic Alfas', but it's worth a search in '75, Alfetta, and SZ/RZ forum.
I had one - I love the styling, and it's a fantastic engine, but as Flo says it's getting difficult to find a decent original one. Keep an eye on the classifieds on here (I guess) and also on the auto-italia website - there's usually a couple on there.
The gearbox was the worst point on mine - sometimes it would be perfectly slick, sometimes a bit notchy, sometimes vague, and sometimes almost immovably stiff. Often you got all of these over the course of the same journey.
It's a great fun car to drive, and the performance is good as long as you bear in mind how old the design is. You're not going to get past many Impreza's in one, but I guarantee you'll be having more fun.