Hi Bluemist,
Usually any competent hairstylist can cut in a unit. It’s 100% real human hair just like they cut all day long. But some customers pay a thousand bucks or more for a unit from other suppliers and this can make some stylists nervous. They are afraid that they will cut off too much hair. And it’s true that stylists that sell systems want to cutin only their own units. I checked my data base and found this stylist in Toronto:

Alexis Hair Experts
Helen Kovavachis
380 Eglinton, Ave.
West Toronto, Ontario M5N 1A2
Canada

It’s best to go to a hair stylist that is familiar with hair systems just to get started ‘on the right foot.’ I’m sure you could fine a regular stylist that could do the job but just to make sure I’d use Helen.
Regards,
John