Why not start with Orpingtons since they seem to have the qualities you are looking for? If they don't turn out to live up to what you want then start again with another breed. They come in other colors than buff if you want something else.
If you were looking for show type stock I know I've seen buff Orps in the past at the Boston Poultry Expo in Oxford. It's held the first weekend in Nov. I imagine there were some at the Poultry Congress too. That's held over MLK day weekend in Springfield. Of the two shows the Congress is much larger. The birds are huge compared to hatchery stock, though I have no idea on their laying ability. I also don't know how long it takes them to reach such a monstrous size.
If you were looking for show type stock I know I've seen buff Orps in the past at the Boston Poultry Expo in Oxford. It's held the first weekend in Nov. I imagine there were some at the Poultry Congress too. That's held over MLK day weekend in Springfield. Of the two shows the Congress is much larger. The birds are huge compared to hatchery stock, though I have no idea on their laying ability. I also don't know how long it takes them to reach such a monstrous size.