As long as the centers have the same back spacing theyll be able to make up new inner and outer barrels to make them all the same width and offset. Have you got a pic of the back of the wheels? (both the 9j and 10j). Brake clearance is determined by two things, spoke design and the hub back spacing, changing offset by moving the center in the wheel has no effect. Judging by that first pic you posted the back of those wheels look pretty flat so spacers would be your only option (in my opinion).
Having said that, theres nothing wrong with spacers if theyre made of good quality material and you use hub centering rings. Plenty of people use them without issue.