just a couple of thoughts. if you don't take your stroller then you will have to carry baby and all your gear through the airport - we still use the stroller in the airport and my baby is 4! It just makes life so much easier.
If you decide not to take your stroller, then I would recommend a sling/backpack for the airport.
If you want a skycot, then phone the airline asap and request it, if you wait until you get to check-in you run the risk of the bulkhead seats already being allocated. I used one when I flew with Katie, and they are brilliant.
I am not sure why you would want to take the carseat to the gate, unless it has a chassis, you might as well just check it with the suitcases and get it in Orlando -one less thing to trawl through the airport.
I would try and get your baby used to drinking unwarmed milk, it will make life so much easier.
What we did was to sterilse the bottles, fill them with cooled, boiled water, and then put them in the bag. We measured the powder into a little pot we bought at Mothercare (has 3 compartments), or even easier, you can now buy premeasured sachets of powder, and then when we needed a bottle, we just dumped the powder into the milk and hey presto a room temperature bottle. My dd was quite happy to drink them like that.
This solves a lot of problems, you don't have to wait for the milk to warm up (and they definitely won't heat it for you, because of liability issues, although I think the hot water in a cup is even more dangerous but there you go), and more importantly, water won't go off, whereas milk will go off pretty quick in the florida heat, so you need to be worrying about cool bags, and ice blocks etc.
Speaking of strollers, and rip-off-britain, Mclaren strollers are superb for the parks because the recline and fold umbrella style, these are MUCH cheaper in the UK. The graco strollers are cheaper in the USA, but be aware they won't have a 5 point harness, and you won't be able to sell it in the UK once you have finished with it. I bought my first pram (a graco) in the States for about half the UK price, but I had no comeback when it broke (which it did quite quickly), the harness was rubbish, and when I tried to sell it to a 2nd hand shop they wouldn't touch it because it didn't have the right UK safety codes.
Saying that, the strollers are cheap so if you are happy with those issues, then they are a good buy.
For babys under a year (and probably older than that too), make sure the stroller goes flat or near enough, so that they can get a decent sleep while you are wandering around the parks.
Bev
(sorry it's long, just a favorite subject of mine)