The martingale: greyhound collar is the only way to go for those of us who have dogs with bigger necks than heads.
I don't think I would ever buy a regular collar for a dog especially if its a doberman or rottweiler.
Shai has a 9 foot black leash with a traffic handle that I use when she is a little rambuntious and I need to control her better. And she has a 16 foot flexi leash that she gets to wear when she plays. I wouldn't want a longer one unless I was anchored to a tree, or I would go flying!!!