I am large breasted too. If you cannot wear a bra I would pass. You also didn't say what the neckline was - you make be able to find a bra that will work. I have found bras at Nordstrom for larger cup sizes that could pull off most tops.
If it has spagetti straps I would pass. If it has spagetti straps they make your chest and shoulder look bigger with a large chest.
There are some good bras that should be supportive for you for necklines like halter.