FYI, the newest line of semi-auto Berettas for trapshooting (Classic Trap or Parallel Target) is the A400 series. There is a parallel target version in this line, but it's not available in Canada yet. There is no "classic trap" version in the A400. Hence your best bet, as noted above, is the 391 series, probably a reduced length stock.
I suspect, however, that it will prove a challenge to find one of these guns.
You could settle for a Remington 1100 semi auto trap gun. Much easier to find, cheaper too.