You can interchange most of the Gardiner poles , just look at the handle diameters and get the next section up .
I was in the same boat , i was taking a clx 27 and an slx 18 to work , all i do now is take the 2 bottom sections of the 27 and put them on the 18 when needed , it used to be a bit of a pain when i used full pole hose but now i run tubeless its a doddle , probably the best change i think yo can make with regard to coiling hoses after every job , and the rectus stays good for donkeys .