If you already have the tools to do the job, I would do it yourself. The investment in the tools will make things more convenient for you because you can service and check things whenever you need to vs having to take
time out of your day to take your vehicle someplace and hope everything can be done that same day.
A/C maintenance is not difficult at all. I do all my a/c servicing and repairs at my house. Vacuuming the system, charging, etc is very easy to do. Been doing it for years.
If you don't trust the shops do it yourself.