how badly do ya want it ?
Today, I walked around my neighborhood with a 18" dish and my Satlook meter ... and found 148 degrees west.
That must've been a sight! -

The good news is, DBS circular is easy to hand-hold, they have a lot of power, and the circular bird is amazingly easy to find compared to linear.
So, even that far away, 18" was all it took, once you had Line Of Sight.
from 135-148 on KU the only thing is 148W
Well, hills and heights notwithstanding, what was the point of motorizing the western arc ?
Are there more Ku birds over there you wanted?
If so, wouldn't you need 30 to 36" ?
How 'bout a fixed dish for 148ºW?
There , you could get away with 18".
But, if there's still some reason I've missed, it might be possible to motor down to 2º above the horizon.
Just not with the typical H-H motors.
If you're really serious, have you considered a polar mount and jack?
I would think you could tweak the geometry of one to handle your needs.
But if worse came to worse, a fixed 148º could still be used in conjunction with a motor for other western birds.