I had a pre-order through Apple with an October 4-10 ship date range (Jet Black, of course). I found a Matte Black on Apple's website and ordered it 'pick up at store' and paid in full. When I went to the store, they refunded that paid in full and changed it to the iPhone Upgrade Program.
Mine was 'preparing' for shipment since Saturday (BS) and it still is. Apple has it set up to re-route back to them when it ships, so all is well.
You do not have a Next agreement until it actually ships, so waiting until you have it in your hand will work just fine.