Is it possible to set a custom cell's textLabel?

You sure can! Just implement the getters for the labels to redirect to your custom cell's labels.

- (UILabel *)textLabel {
    return self.myCustomCellTextLabel;
}

- (UILabel *)detailTextLabel {
    return self.myCustomCellDetailTextLabel;
}

For people using Swift:

var textLabel: UILabel? {
    return myCustomCellTextLabel
}

var detailTextLabel: UILabel? {
    return myCustomCellDetailTextLabel
}