Cat glucose monitor?

My 13 year old is usually on 3.5units x2 day of Prozinc. But I the beginning of January she had some really bad constipation for two weeks. And wasn't eating. We started her on Lactulose (which is very sugary) but this past Sunday just as she was starting to recover she went Hypoglycemic and had multiple seizures. The vet had been checking her glucose levels and they are a lot lower then she usually is. She's still not eating as much as she used to much with the lactulose they wouldn't be this low. We think she might have went into remission sometime recently but we didn't notice with the constipation. So now we are starting to monitor her glucose at home.

Which cat glucose monitors do you recommend? My vet said the super expensive one they use there is unnecessary for home use so I'm finding a cheaper one. I've never used one before so I would like to to be easy to use. Thank you for your help!