Why only them? If i break something, 9/10 times i know in 1 sec where i have to go to fix it. Dont only target them! Target at all the people in your niche. They have to know you for the moments they really needs you guys!
So also make some great explanation videos about the stuff you repair when its not broken yet:)
Make some videos how people can fix the simple stuff themselves. So they know where to go with complicated stuff.
Just use MP to use them all and test the shit out of it! Then you can see what platform suits you at the end.
Try to hink outside the box. But you can start with the usual stuff. Target quality accounts where you think your followers are.
And read,read, read at this forum. You can use the search function and you will find so many good quality stuff!