BLUE TONGUE SKINKS

Hi there. Last year my corn snake died of a GI parasite presumed by our exotics vet to be cryptosporidium although tests were inconclusive. I’ve been doing some research and have found a website (I’m in the UK) that provides faecal tests for reptiles as I would not like this to happen to Stevie my blue tongue. I was wondering if anyone has any experience with this website and whether they know which test I should choose from the ones I’ve attached photos of.
Thanks