You probably maintain orientation with a control moment gyro and periodically desaturate it with thrust. You also use thrust to reboost and stay in orbital slot.
High-impulse ion engines, etc, are a good match for this task.
You'd need a rigid structure to keep the gyro from ripping itself loose from the structure. Even constructed as a giant space frame, that's a lot of mass to deal with the torsion of the structure rotating.
A structure 100m on a side would be just at the bounds of current technology (the ISS's control moment gyros). With 30% efficient panels that's only about 4MW before conversion and path losses.
The high impulse ion engines to desaturate the gyros would still need to be refueled regularly. I think you're hand waving a lot of complexity that even if completely solved still leaves a solution that's orders of magnitude costlier than solar panels on the ground.
This is exactly how the NOAA GOES sats work. Every day at a proscribed time we used to desaturate the reaction wheels, so they could more or less keep running constantly and keep the satellite pointing where it should be.
Yup. This would be big enough that a control moment gyro would be "worth it," too-- and could store a whole lot of momentum and allow less frequent desaturation burns.
High-impulse ion engines, etc, are a good match for this task.