Quote Originally Posted by Karen
A regular flat collar, and start working on him NOT pulling right away. If you do this now, when he's a baby, you won't have to resort to prong or choke later.

This is what we did with every one of our dogs, one mostly-Dane who grew to 145 lbs, and two Saint Bernards, 185 lbs and 155 lbs. None of them ever pulled past the first week of training - when they knew the person holding the leash was paying attention.
I guess it's because Labs are more hyper than Danes, but at 1 year old Nova is still wearing a prong collar when we go out (friendly dog syndrome - she pulls on me when she sees anyone!). We train often, and she is awesome when we are in our neighborhood or a secluded area, but if she sees one person or dog (or any other animal for that matter) she is pulling hard!