i reckon you should just suck up and buy the smaller kite. i found a used 7m rev fairly cheap (same price as a board), and it is the mst fun to ride with. great in 20ish on surfboard, or sick for when its hell windy on tt.
you certainly wont regret buying a small kite, only when you get hell edgey between decent winds. hahaha

EDIT: i thought a main kite for WA was like a 7m. haha. maybe you need a 5m.