I doubt you'll get much flavor out of any yeast you add at bottling. Champagne yeasts, contrary to popular belief, are not highly attenuative in beer. They're very good at fermenting simple sugars, but will not metabolize maltose. I'd just use Nottingham or US-05 for convenience. If you want something really attenuative, try 3711 French Saison, but watch out, because it might drop your FG significantly and give you bottle bombs.