I speak with limited experience, but as a rule the stone fruits are pretty given to compatability, so I'd be surprised if the sweet cherry would not be happy on the ornamental cherry.

"Wild cherry" is almost a generic term, there are so many types, but again, it might well be worth a try.

Keep in mind that just because you can get a scion to take on a different rootstock there is no guarantee that the scion will be compatible over a long term, and there's also the real possibility that even though they mate well that the rootstock dwarfs the scion or, conversely, that the scion overgrows the rootstock rather grotesquely. Rootstocks can be invigorating or de-invigorating with even their good friends! But some of them do play nice together, and it's lots of fun finding out.

Good luck,

M