I honestly would suggest that you take a weekend and drive to the largest centre near you that sells tuxedos and get the best one that you possibly can. Do NOT purchase one of their used ones either. You want to look your very best and a tuxedo is your work uniform that you will use so invest in it. You want it to fit you perfectly (something that will not happen if you purchase it on-line) and look the best possible on you. Do not skimp or try for a cheap route as it will look like just that. You really do get what you pay for and as perception is everything, your audience will see that reflected on you the moment you walk out in a quality tuxedo.
Paul Alberstat http://www.stores.ebay.ca/Abstagecraft
(Make sure to check for our January super special)