However, depending on how long your vacation is, you may not need that many diapers that come in one box and will essentially be bringing home 3/4 of a large box, anyway.
We've shipped ourselves water from Staples in orlando; it's I believe next day local delivery and I ordered it online. it was great and super cheap - we had three cases because there were alot of us for a week. the only problem is that we didn't know where to pick it up. Front desk kept saying it wasn't delivered (we saw the staples truck as we got on the bus so we knew it had been). we finally tracked it down at the bell hop. They also have snacks you can order too.
If you are interested in other items try Garden Grocer. We have used it many times, no problems and great service. Always at our resort when we arrive. There is a delivery fee.