Architects and Engineers are also limited by their Errors and Omissions Insurance as to what they can sign and seal from a liability standpoint.
Depending on the complexity of the building, an architect may have a structural engineer review the foundation and roof designs as well as header and column sizes. In that case, you probably end up with both an architect's and engineer's stamp on the drawings.
Ask the building official that will actually be reviewing the plans. While state law may mandate an architect, there might be some leeway in what is actually required. The building department's main concern is that the building you are putting up is designed to meet local frost conditions, wind load / weather factors, and meets the other parameters of their locally adopted / amended code to be a complete and safe building.
In instances of larger projects, the architect of record typically signs off on the entire project while the civil, structural, mechanical, electrical, plumbing, and other engineers sign off on their portion of the project. Ultimate responsibility falls back on the architect.
Double check if the building department wants original "wet" stamps / impressioned seals or if reproductions are acceptable. My guess is that they want all originals. It's a good thing to know before you pay for printing of drawings.
I would also keep an original set of stamped drawings for my records if I were you.