My recommendations for BMOQ
The clothes you have with you for the first 4-5 days, think of them as Throw Aways. I tore two of my shirts during the first 4 days moving around and it was a shame since they were my favorites. Make sure to have suitable suitcases(with EXTRA room) for when you make trips into Montreal on days off for shopping.
Underwear is underwear, what ever you want to wear wear it, I would suggest NOT buying new kinds/stuff to take to basic, it would REALLY be a bad idea to have underwear that chafs in the wrong areas while on a 13km ruck.
Quality Iron: buy it and keep it safe, it will be used DAILY.
Swifter clothes and dusters, Buy them in Bulk, you'll need them.