We're using Lantus (10 ml, 100 units per ml) and got the syringes by prescription from the vet along with the insulin, so I guess it would be U100. Our syringes do have half unit doses... my problem is that the marks are SO tiny and it's really hard to see them with the black plunger. I guess most cats get more than 1 unit but our cat is on 1 unit right now and it's really hard to see.
Our vet didn't give us any information about home testing but we picked our cat up from the vet at a late hour when there was only a tech there to show us how to do injections. We have no idea how to do testing and to be honest I'm frustrated that our vet told us nothing about getting started with it.
They gave her her first injection on a 10 am/10 pm cycle and now we have to get her back somehow to 7 am/7 pm because my mother cannot do this alone at 10 am and I need to be there to help before I go to work. The vet said we could gradually move the time back to 7 am/7 pm.