I can do a few spots
from x = 50 to x = 15, I can do y from 100 to 240, perhaps higher
from x = -69 to x = 70, I can do y from 110 to 140, perhaps higher
at x = -108, plus or minus a block, I can do y from 80 to 95 and 105 to 125
moving from x = -108, I lose like 3 blocks of altitude per block away
so i can do y = 105 to 116 at x = -105 to x = -111
from x = -28 to -39, I can do y from 100 to 120 and probably higher
as for machine size, i think 5x5 will do for now, though a larger 15 x 15 or 5 x 20 (think flying carpet) window might be very useful