Hello!
The project description didn't define if you want a traditional or digital painting, so I'm bidding in hopes that you are willing to accept both kinds.
Taking our locations into consideration, and the longer time taken to finish a traditional oil painting, I recommend digital art. I use a software called Rebelle, that mimics oil paint really well. That way you can print the painting in any graphic shop you prefer, in the size you prefer.
I have a portrait example of art made in that software in my portfolio, if you want to check what the software can do, or what I can do with it.
As the milestones state, I'll send you a sketch in graphite for half the payment, and the digital painting for the final payment.
I'm sure you understand that I have to watermark both images and send them in a low resolution, and send you the full res picture afterwards.
In any case, I hope you can find an artist you like, even if it is not me.
Good luck!