There are no tools for managing Liker's with a Page. That's what makes it easier to administer than a Facebook Profile.. anyone can Like the Page, it doesn't have to be done in both directions (each user friending each other).
Inside a Page's settings, you can restrict who's allowed to post to the wall. As for sending a message, when the admin posts to the wall, it can show up on all the wall's of the user that Like'd the page automatically.
As for migration tools, again, there aren't any. Facebook would want that user to use a Page instead of a profile, because usually, people with 1000+ friends are simply mutually friending everyone, and not talking about personal things, but more career or product promotion. That's the intention of a Page (lots of followers with a central theme). To do so, they'd need to start a Page, and then post to their personal profile to follow them there (Like their Page). It is a big task, but unfortunately, that's how Facebook has things setup and wants them to do it.
Finally, use Google and search for "Facebook Friend Limit". You'll see many discussions about this. The max friends a user can have is 5000. If you hit that, you simply can't have more. The recommendation, across the board and by Facebook, is that you should have been using a Page in the first place. That's their purpose, as with 1000 friends, your clients likely don't know each one personally, which is how a profile is supposed to be (close contacts).
Hope that all helps explain. In short, start again, but use your existing profiles and website to promote the Page heavily.
Alex