I don't think it's going to happen. I chatted with Apple and they said it's up to the store to get a device from the warehouse without it being paid for.
So I chatted with a business rep at my local store who said they can't accept payment for a refurb because it's not in their system. (Even if I returned it and bought it again right away).
Then I asked if I could do that with a customized Mac Pro or iMac, again they said no, I'm not sure why but whatever.
They did say sometimes they have different configured models in the store that don't show up on the website so I gave him my min. specs and hope I hear back before the end of the year.