Myself, I would do the work myself. I can't afford to pay someone more than I earn to do something I can probably manage.
If you want a wall mounted light fixture, you will have to fish your wires down to the wall and had a box their. Hopefully there is a stud nearby to support weight of your fixture.
I would leave an box on the ceiling portion also, because you will probably will have to get to the pigtails you spliced into this system. This will be covered with a blank plate painted to match the ceiling.
The Drywall isn't too difficult.
This job can be done in 2 or 3 visits if you do the painting yourself. Have to leave time for the Drywall compound to set.
If you did this yourself, materials would cost less than $10 + the cost of your new fixture and maybe your paint.