Some of us think that "six feet" is a magic number. That is, any keel more than six feet deep will be problematic in a lot of areas and probably constrain your buyers to those who race and cruise further offshore, or in deeper waters. She'll never sell in Florida or to folks going into the islands, but that's just the way it is. On the other hand, she should point upwind and move faster.
Iron keels come iwth the territory, I suspect Jeanneau and Beneteau use them because they are 'good enough' and reduce the selling price substantially compared to lead. Find a similar boat with a lead keel, check out the price, that should speak loudly.
What can you do, choices have to be made.
Of course, if you feel really lush, you can contact Mars Metals and have them fab up a proper lead keel for the boat, in any style you please. I wonder if Jeanneau ever gets requests to "deliver one without a keel". (G)
Of course lead keels are pretty much a cheap man's option, too. After Berty Roos (?) lost a borrowed spent-uranium keel in the Southern Ocean, I think governments got a lot less interested in loaning out THAT excellent material. But, you can easily buy tungsten on the open market. Safe to handle, easy to obtain, about twice the price of lead and twice the density as well. (Start collecting all those old light bulb filaments, now.(G))