Halloween Costume help?

[Elennare]

Ok, so my original plan for my Halloween costume this year fell through on account of lack of time to make it.  My husband has decided to be Captain Hammer, from Dr. Horrible's Sing-Along-Blog.  He jokingly suggested I could be Dr. Horrible.  The more I think about it, the more I'm liking that idea.  Still not sure, but it's growing on me.

Here's my question.  Dr. Horrible has a really neat lab coat.  Here are a couple of pictures of it (sorry, couldn't find any good full-body shots):

http://drhorrible.wikia.com/wiki/Dr._Horrible
http://www.wired.com/underwire/2008/07/joss-whedon-tal/

Do you think this style will work, without any tweaking, on someone who is rather busty?  I'm concerned about it gapping oddly on the side with the closure.  If it does need some tweaking, what should I do?  I definitely won't have time to make a bunch of mock-ups, so any suggestions that will help me get it right w/the first mock up (or even just a first go w/the real fabric) would be greatly appreciated.

And if anyone has any suggestions on a costume for a 16 month old that would go with those 2 costumes, I'd be interested to hear that as well.

edit:  I should probably specify that the 16 month old is a boy.

[Hoowil]

Add a line of velcro down the closure, or fit it so the openning is false?