Yes, Uber is a realistic option.
You might also want to consider Uzurv, because not all Uber drivers want to make a long trip like Sanford-WDW.
Uzurv allows you to place a ride request, have drivers indicate interest, be able to review driver profiles and select a specific driver, and then schedule the ride. All of those rides are then conducted on the regular Uber/lyft app, so you get full insurance coverage and pay normally through the app. There is a nominal Uzurv fee ($2.99, but only $.99 currently as an introductory offer).
Both Uber and Lyft offer "pre-scheduling," but those are nothing more than pre-programmed ride requests that go to the nearest driver at whatever time the computer spits out the pre-scheduled request. Nothing special, and they often result is way-early requests and cancellation fees. You are WAY better off just requesting a ride normally. Uzurv is the only real, reliable, effective pre-scheduling option.
You can check RideGuru for comparative prices for taxis, Uber, Lyft etc.
Another option (which I have never used) is a one-way car rental -- renting at the airport and dropping off somewhere onsite. We'd have to know where you are staying to know how feasible that would be, and you'd have to check several companies to see which deal was better.
