Hi Stephanie,
Although I don't know the exact count, there is a fairly large number of strollers available at the Magic Kingdom. Strollers are available on a first come, first serve basis when you arrive at the park and advanced rentals are not available. If you arrive fairly early in the morning, you should be okay.
The strollers are made of hard plastic and do not offer any padding. I personally don't think they are very comfortable but they do serve their purpose for those families who aren't able to bring their own strollers. They do have a small amount of storage space and do have a canopy. Strollers are not allowed to leave the park in which they are rented so at the end of the day, your kids will have to make it back to your resort or parking lot under their own power or yours.
The stroller rental fee (keep in mind this is always subject to change without notice) is $15 per day for a single stroller & $31 per day for a double.
For more information on stroller rental locations, click
here.
Wishing you many magical memories :-) Allison