Generally speaking, I would strongly recommend an overhaul from a local shop over a McParts store rebuilt model. A lot of the low-end rebuilds have received nothing more than new brushes and a fresh coat of cheap paint.

Either way, have the replacement alternator tested before you install it.

Considering that your alternator seized up, it might not be economically repairable. And it might not be acceptable as a core. But the local shop should be able to determine that pretty quickly.