Any of the lillypilly family [syzygium] would be good because of the dense foliage and fresh , almost citrus smell , the folliage will remain soft if pruned reg. golden penda or the xanthostemon could also be suitable as it grows upright with few lateral branches so way less pruning and it produces a showy yellow flower. cheers and good luck, you could always try tabacco, the flowering kind.....very pleasant smelling but lacks the height you require.