I havnt any experience of Kawasaki GT 550 but Mechanics here in LAhore & Karachi didnt recomend it as there parts are not easiliy available & there are also some durability issues after engine builts however Bikers from Isloo/RWP can comment better on it as there lots of GT 550s on streets as well as in Junkyards.
As per my info & experiecne SUzuki GS & GSX series bikes are the best suitable for long tours here in Pakistan. New & used parts are easily available as compare to Honda CB/CBX & Kawsaki GT 550.
Also a wide range w.r.t engine capacity is available for this series among Police/Forces auctioned & private Models,
GS 450 E
GS 500 E
GSX 750 P