I think Em, A7, B will work perfectly well as well. The sequence you gave would transpose from:

Fm Eb7 Ab Fm Cdim Bbm7 C7 Fm. Fm Ab Bbdim Fdim Cdim Bbm7 C7 Fm Bb

to:

Em, D7, G, Em, (B), (Am), B7, Em. Em, G, (B), (Em) (B) (Am) (B) Em B

Substitutions are in parentheses.

Regards,

A