Hi Kirsten,
Disposable diapers are available on the island but brand and size availability seem to change on a weekly basis (many of my clients make this request). North American brands of cheeses are usually available and I believe the local milk is pasteurized; box milk is a good alternative.
Let me know exactly what you're looking for and I'll check with a couple of my suppliers for you.
Regards,
Simon...
Lagniappe Provisioning
www.lagniappe-belize.com