As a brand new Too parent (with some previous experience, but this is my first time owning and caring for my own U2) I have been reading until I can't see straight to find out all I can about these birds. So even though new, I feel I can safely say that this doesn't sound like the best situation for a big Too- living in an apartment, I assume you have close neighbors- Too's can be way too loud for apartment living. Bothering your neighbors may even have your landlord asking you to leave your new place. And as for you and your gf working all day- this is not the best scenario. I'm sure there are some Too's who handle it just fine, but from what I read, most wouldn't, as they need much more interaction with you then many birds. Bored or unhappy birds (because you aren't there all day to be with them, and they are just stuck in their cage by themselves) are trouble. They could start plucking all their feathers out from boredom and unhappiness, and/or scream- possibly for hours! And of course you won't know if the Too you get is one who can entertain themselves for hours, or one who will scream for hours, until you get them into your home. I recommend you google cockatoo screaming to hear how loud they can be.
I guess I would ask myself- what if the bird I get screams all day? What if my landlord then says I can't have the bird? What if my bird starts plucking all it's feathers because it is miserable being left home alone all day by itself? What would I do in each of these scenarios...
They are amazing creatures, beautiful, and so sweet.... but the amount of care they need is daunting even for myself, who works from home, in a decent sized owned home in a rural setting where neighbors won't be bothered. Having already had an issue with my first adopted Too, who wound up being very aggressive and I wound up having to return him to his owners and adopt a different bird (who is a doll, but still a LOT of work to keep happy!) I'd hate to see anyone else make my same mistakes, as it's the bird who suffers the most. It was heartbreaking for me to have to make that decision, as I know how hard it can be on the bird for everything to change like that, going from one home and owners to the next. Deciding to adopt the 2nd bird I had to make the decision that no matter WHAT happened with this new bird, she was here to stay and I was committed to do everything necessary to keep her happy.
If you're still set on a big Too, my best recommendation would be to go out and meet as many as you can, spend time with them, get an idea of their different personalities and needs. And know that just because they seem sweet and perfect when you meet them does NOT mean they will be that way when you bring them home. You need to be absolutely committed to doing everything this bird needs to adjust into your family and be a happy well-adjusted bird- the bird may come with issues that the previous owner never mentioned (or never had, but now does because of the new environment) and you now need to work through them, with training, and patience for weeks or months before it becomes the bird you thought you were getting. And you need to be prepared for breeding seasons, where your bird may change a LOT in response to hormones- perhaps being louder, more destructive, and even aggressive. So there is a lot to think about.
GL

I hope you find the right bird for you.