It has been my experience that only Scooterbug is allowed to deliver directly the Disney hotel bell services. I suppose you could meet a third party company at the hotel entrance, if your schedule allowed. We wanted to have the scooter ready for our first morning, and didn't arrive until 10pm. So Scooterbug was the best option for us.
I know there had been some poor reviews a while back, but we found the scooter in great condition and the battery lasted all day when fully charged.
There is a scooter rental location in the lobby of the Best Western Park Place Inn, across Harbor from the gates. It is very convenient, especially the year we stayed at that location. But again, your schedule would need to allow the time to get it. I believe they close at 6pm?
I hope this helps!