BMW in KSA
Depends on what kind of bike you want, but Tristar have a very good deal on K1200RS, '04 models, brand new, which around 50 people have bought so far. Excellent sport tourer for 1/2 price of new K12S.
Abdulrahman Al Mutlaq on +966 505440396 or firstname.lastname@example.org
He has a BMW / KTM and more recently Moto Guzzi showroom, and a mainly BMW workshop.
Harleys very popular too, good value if you like them.
Others available but workshops not really developed, to put it charitably.
Not worth buying a bike and importing it, as far as I know, hassle and warranty etc.
Licence - it should be possible to exchange it for a Saudi licence, you need support from your sponsor's PRO but what you have would do to get on the road imo.