Nails,
Your Mangalitzas will be fine, but are different from the OSB's in that they have sight, so can see you coming!
We have found ours are much more forward, even pushy, so make sure you don't let them rule you. Once tamed, they are fantastic and very placid, and hopefully yours will come having been educated on humans !
If they are less than perfect, the trick in the early days is not to let them get distance between them and you, ours seemed to like to charge at us, so keep close to them and they cannot get speed up. Once they arrive, they don't seem to be bitey, but can catch you off balance !
Make sure you pencil in time for them to really get them used to you, particularly the boar !
As for breeding and piglets, there is lots of helpful advice here, and various books (including ours) to guide you through, so make sure you read up and prepare.
I'm sure you will enjoy them