Hi Allene!
Thank you for bringing your question to the Disney Parks Moms Panel!
It looks like your trip is coming up very soon! How exciting!
My boys are teenagers now, but when they were little I was a huge fan of the Walt Disney World double strollers. They're very sturdy, roomy enough for two boys (or one boy and lots of bags!) and the wheels are big enough to easily get around the parks.
Walt Disney World Stroller Rentals are not currently available to make in advance. You can purchase your length-of-stay rental at the first park you enter. Save your receipt and then simply show it at each park you go to when you need to pick one up. The strollers stay in the parks, though, so you will need to get a different one each time you enter.
There are some companies that offer advanced rentals. In the link above to the stroller information page on the Walt Disney World website, you can scroll down a bit to find the information for some of the featured providers.
I hope this helps! Please let me know if you have any other questions and have a great trip!
~Lori