There is no one right answer for all of us. We all have different goals and circumstances.
There are a lot of differences between the broilers and DP other than feed to meat ratio. DP mature later so the meat has a different texture. You feed and manage them differently. There is not as much breast meat on DP. You don't have to process the DP at a specific time to avoid the medical problems. Plenty more differences.
You might consider getting some DP and maybe raise them with your Jaerhons if you have room. See how it goes. You can always go back to your other system if you wish.
As far as breed, you will find people in love with any of them. They are all called DP for a reason. Just pick one that you think you will like and go for it. If you pluck, I'd consider a white or buff bird so the pin feathers don't show as much and you get a prettier carcass. But really, any of them will work.
Good luck!