don't know if she is still shipping at this time but this place has both of your trees. i ordered sourwood from her a few years ago and it is doing fine.
i think they are not expensive at $6.00 and $8.00 each for an approx. one-gallon size specimen.

Here is a link that might be useful: mailorder natives

I bought a small sourwood from Earth Touch Nursery in Huntsville several years ago. You might check at Bennett's also.

I used to have Sourwood seedlings everywhere at my previous home. They are very prolific. I imagine I have them around here as well, as there are several mature Sourwoods on my property. I don't know whether I would feel 100% confident in identifying them, though -- otherwise I could dig some up!