First and Third inversion chords in circle of fifths progression:
C: I, V6, I
Soprano: C, D, C Alto: E, G, E; (another Alto): E, D, E Tenor: G, G, G (Bass notes found from inversions) We have to go to D in the soprano line to avoid parallel perfect octaves with the bass, and to avoid doubling the third (which happens to be the leading tone).
C: I, V6/5, I
Soprano: C, D, C Alto: E, F, E Tenor: G, G, G (Bass notes found from roman numerals and inversions)
C: I, V4/2, I6
Soprano: C, D, C Alto: E, G, G Tenor: G, B, C (Bass notes found from roman numerals and inversions)
Another option: Soprano: C, B, C Alto: E, D, C Tenor: G, G, G
Voicing a viio using functional substitution:
C: I, viio, V6/5, I
Soprano: C, D, D, C Alto: E, D, F, E Tenor: G, F, G, G (Bass notes found from roman numerals and inversions)