Orbiter is closed-source, so Dr. Schweiger would have to port it and do all of the work. It would also require an entire rewrite of the graphics engine, as DirectX is only available on Windows.
It would be cool, but it would take a lot of work.
In more general fashion, Orbiter is also built on Windows programming concepts like handles, which would make rewriting the program damn near impossible, and also force a rewrite of every add-on ever made for it. Not just a recompile of the source of the add-on, a complete rewrite of the code. That probably rules out UMMU, UCGO, IMS, the XR Fleet, every launch vehicle, AMSO...
I would guess the Windows Surface tablet could be a contender? It has an attachable keyboard. Forget how much it costs though.
Surface Pro + any keyboard should be enough to run Orbiter. But $300 would be a good start into getting a financing loan, not more.
Surface (RT) can also use ANY USB device, that Windows can handle with its drivers - even wireless keyboards - no need to use this strange touch cover keyboard.