No, the official post says "These pre-order bonuses will be offered exclusively through participating North American retailers and will be made available in Europe and Australia in the coming weeks." which means that this will be the only way that you can get those items. There is a chance that the bonus packs will become a DLC later on, but the wording makes me think that's unlikely.
But, if you can somehow get your hands on more than one unlock code, I imagine you could use them. I'd probably even be willing to pay someone for a psycho unlock code, but I'm not really sure how to arrange such a thing.
Oh my, That's not cool, exclusive weapons to only selected retailers. I mean, DLC would be nice. But to have it locked on certain retailers kinda svcks. I'm 16, I got my learners license and all but no Visa card to buy from Amazon or whatnot, and I doubt mum would let me use her Visa/Credit card etc.
And I have this thing, I love to play, "crazy" looking characters, like Mmorpgs = assassins types. So this psycho pack is that "crazy" thing that I'm after ..
and not to have it available is just sad
I'm not saying it would make me not buy the game, that would be immature since that is just one of many things the game offers.
Thanks for a quick reply.