Try first choice, just checked and it worked out as £2183 staying in the Quality Inn with car etc but it is from 21st August to 4th Sept.
What about Travel city direct, i priced them up as £2699 flying on the dates you want, 2 adults 1 child staying in Disneys POP Century including car and insurance. If you wanted something cheaper there were lots of hotels off site from £2400.