Hey there! I'm sure there are some great UK'ers that will know more about scrapping over there. As for the Dis, we have a very active scrapping community here.
If you go out to the main board and down to the Creative Community thread, select that and then go down a little bit again you'll see the Scrapbooking board. Have both paper and digi scrappers over there, and at least one UK scrapper. (link below)
As for scrapping at disney, they have a disney scrapbook store at Downtown Disney. I can't remember what they call it. Honestly, it's only so-so, but you could get some papers and binders there and then supplament. Don't buy the patterned scissors. You can't cut a thing with them, at least I've never been able to. The punches are nice though.
Now, I don't kow if you will be renting a car or not? If so there's a place somewhere around Orlando that's called Mouse Memories that's supposed to be nice. Also, just from what I think I understand but I might be wrong scrapbooking supplies cost more and are hard to come by in the UK, plus there's the high cost of shipping; however, with the exchange rate being what it is it's better to buy it when you're over here and take it home with you.
I would ask the UK scrappers on our scrapper board what they think, but if you really want to lay in supplies for winter, you could hit AC Moore and Michaels while you're here, again if you have a car. Or you could go to the Creative Memories webiste and find a consultant in the Orlando area, buy what you want and they would probably meet you at your hotel and give it all to you there. Obviously I've never done any of this and there may be problems I'm not considering, but I just want to give you options.
Lastly, you could just go to digital scrapping and then it doesn't matter where you live! LOL There are threads about digi scrapping on the scrapping board, too.
Either way I hope you find what you're looking for without too much hassel. And if these are you first books, good luck, I hope you love it as much as I do, and don't forget to post your layouts on the scrapping board:
http://www.disboards.com/forumdisplay.php?f=123