I've always had good service with Big Cheese, too. This is from their FAQs (I don't know where you're located):

Do you ship feeder rodents internationally?Yes, we do ship rodents internationally, but some restrictions apply. Please call our sales office at 817-926-3300 for more information.

Also from their FAQs, since you said you have a small collection:

How long will the frozen feeder animals last in the freezer?Our rodents have a shelf life up to 2 years when completely sealed in our Cryovac bags.

You could always make a bulk order and then just open one Cryovac bag at a time and transfer the rodents from the bag you open to a Ziploc bag, then use as needed. That's what I've been doing and haven't had any issues with freezer burn or anything.