Good choice on the BMW. I picked up a F650GS out here and it has been fantastic, though a bit heavy for the brakes with two and stuff.
GPS... I wouldn't. I have never used a motorcycle GPS but the car versions I have tried in Korea (Hyundai and Garmin) have led me so wrong I have sworn them off. My preference is a good ol map on my tank bag and reading the road signs. If I get lost, the smart phone with naver/daum/google maps is there to save the day.