Will the eaves of the garage handle the weight and remain stable as the dish rotates, as well as in the wind?
I have boxed-in eaves on my house, and still put a stiffener 1x6 all along the section where I was going to put two little dishes.
I used lag bolts to secure everything in place, into the ends of the rafter tails.
It's been fine for two years, but I only have a 20" and 18" dish, well below the peak of the roof.
Nice 'n low to work on, and not visible to most, as it's in the back.