I think these actors are the best choice for future characters

Abraham Ford: Kevin Durand (credit goes to Ckarimalis)

Rosita: Sofia Vergara

Eugene: Jorge Garcia (I know he's a weird fit, but I would like to see him do more work.)

Garbiel Stokes: Harold Perrineau (Sorry not good with actors who could physicaly resemble him)

Paul "Jesus" Monroe: Collin Cunningham

Heath: Nyambi Nyambi (actually his name)

Nicholas: Kiefer Sutherland

Negan: again no idea so I'll say Bruce Willis

Aaron and Eric: Neil Patrick Harris and David Burtka

Please leave your ideas in the comment section below.