Dairylea and marmite sandwiches are my DD's favourite!
You can get marmite at a shop in Old Town, Kissimmee. I don't know what it's called - it sells UK food and has a union jack outside! It's much cheaper to take your own though. We usually take it with us. There's usually a small UK food section in the larger supermarkets like Goodings too. I haven't seen Dairylea anywhere though!