Boots is the single most important piece of gear that is more important than your board or bindings, so if you plan on taking on snowboarding as a hobby do NOT skimp on your boots
Maybe you have heard good things about the Burton boots but dont over look other brands either. Try on as many different pair of boots by as many different brands as possible as they all fit differently.
I generally have to size UP when I buy boots, im a size 11 foot and normally I have to buy 11.5. If your toes are already touching w/o socks more likely than not its going to be too tight with board socks on. Thats going to lead to unnecessary foot pain, numbness, cramps, and will end your day prematurely
Make sure the boots offer good ankle hold, when trying on the boots lean forward like you would onto your toe side edge and if you feel your ankles are not properly supported or lifting out of the liner than these boots are not for you. Commonly people will over tighten their liner and boot to remedy the heel lift but that will only lead to poor blood circulation into your foot and lead to the same as above, unnecessary foot pain, numbness, cramps, and will end your day prematurely. Your ankle should be comfortably cradled in the liner and not lifting out of the boot when on toe edge.
anyways ive said too much....go try on some more boots already