I did the same work according the very good description of Bill this summer. With the right tools easy but not nice work. I ordered the copper at onlinemetals.com in the US. Just to let you know what we payed it was 95$. Maybe you get it cheaper in Europe.
The copper we used is much thicker than the original one of Amel. Our once was almost gone it had just a thin connection. The previous owner emptied the bilge always when he left the boat (he just used it for vacation) maybe you can prolong the lifetime of the copper bar by doing this, but with a new thicker copper bar I assume that the lifetime of the bar is automatically much longer.