Of those 3 options, I would not choose to leave my glider's at the vet. I think the sounds of multiple other animals around the gliders would be very stressful for them and they would also probably be housed in a much smaller cage than they are used to.
If your breeder is willing to care for them while you are away that would be great.
Having someone come in to feed them and check on them daily is also a good option.
When I travel my son feeds the gliders and takes the plates out in the morning. I prepare the dinner plates for each of my 3 colonies for the number of nights I will be away. He just needs to take the nights dinners out of the freezer and put it in each cage. He feeds them earlier than I usually do so he does not have to worry about them trying to jump out of the cage when the door is opened for play time.