Do you have a whipping siphon? Way easier to just use a whipping siphon with nitrous oxide, the whole process doesn't even take five minutes.
If you really want to go the sous vide route I would seal the oil and aromatics in a bag and leave them for three hours at about 60°c. Obviously this isn't going to get close to a high enough temperature to kill botulism spores so the oil would probably need using that week.