Lots of good advise so far.
Take whatever your baby is eating at the time of the trip. I completely agree that on vacation is not the time to try something new. If it's ready to eat then I'd probably ship most of it but take some 'just in case' because it's heavy. If I had a car or car service from MCO then I'd stop and buy what I needed on my way to WDW. I'd pick up diapers, wipes and disposable changing pads too.
I'm a mom of four and taken all my babies, all at different stages of feeding, on all kinds of trips

They all seemed to eat/nurse differently, so in addition to breastfeeding I've traveled with pumped breast milk, powdered formula and ready to eat formula. The powdered was the easiest for me because I didn't have anything heavy to haul (I'd just buy water as I needed it) and there was nothing I had to worry about keeping cold.
My bottle babies all used Playtex Nursers, so I only had to worry about the nipples and bottle holders. I'd rinse them after the feeding, then at night wash them in hot soapy water or run them through a dishwasher. Having the disposable liner was a dream for travel. I love the suggestion of the Enfamil glass bottles if that's a formula your little one likes. Hot, soapy water or a dishwasher would be fine for your bottles if you don't want to haul the sterilizer with you.
Disney parks are awesome with because there is always a quiet, pretty place to sit for a feeding.