Shouldn't be a problem at all. I would call the CFO and see if they can give you your PAL# before the card arrives - (it can happen, I've witnessed it.) Also, The vendor will likely sell you anything you want that isn't restricted. They just won't release the items to you without checking your PAL#.
Edit* I should add that if they do give you your pal number early, it's on you to only possess firearms legally, i.e. while also in possession of your pal card.
Edit* I should add that if they do give you your pal number early, it's on you to only possess firearms legally, i.e. while also in possession of your pal card.