I like Chloe best from the first names and while Chloe Rose sounds nice, I think Rose is WAY to common as a middle name, so I would use a differnt middle name. Chloe Grace or even Chloe Immogen would be nice. There is no rule saying middle names must be short . I love the idea of using a middle name that you really like and would use as a first name iukwim. Where I live I have never met a baby Chloe, and I have worked in childcare for several years. I have met school aged chloes but not too many of them either.