If you do not mind the wrong roof shape there is a Biscayne resin kit by R&R. They took the Impala and added a B-pillar. Alternatively you may swap the roof of a Jo-Han 6 Windows 59/60 cadillac and add the B-Pillars yourself. This, however, this is not a trivial task, because the Jo-Han roof does not fit the Revell 59/60 Chevys. Probably there is a better chance with an old El-Camino or S/D. I tried to do it with a 59 Impala but soon discovered I am not so talented.
Probably conversion to a sport coupe is an easier task. In that case you will have to carefully modify the Impala chrome trim, or cut it from an El-Camino or S/D kit (or is that a Biscayne trim ??
). Additionally, the middle tail light must be removed to have the dual tail lights of the Bel Air.
Photo etched scripts and emblems are usually included in the Model Car Garage Impala detail set.