my %objects;
for my $class (@available_classes) {
    eval qq(require $class);
    if ($@) { # you can make it die() here, if you want
        warn "Failed to load class '$class': $@";
        next;
    }
    $objects{$class} = $class->new;
}

##</code><code>##

use UNIVERSAL::require;
my $class = get_implementor_class(); #defined somewhere
$class->use or die $@;
my $object = $class->new;