Servos - Coreless or Digital?
Weight should be everyones concern... the more it weights the higher the wing loading and the easier it stalls. Anything you can do to keep it lighter will show when it's flying.
In a .60 warbird like yours there isn't really a need to go digital. A good set of analog coreless servos will do just fine. If you fly Futaba I'd recommend the 9202's and if you fly JR I'd suggest some 4131's or 4721's.