I have a Brody (it's Irish, not American)...so obviously love it. Brodie is the Scottish spelling. Keir/Kerr is nice. I had it on my shortlist! Blu...maybe a middle name? Not a first name I don't think.
Agree with wolfie. Brody/Brodie is fine if you have Celtic connections. I have a feeling I read somewhere that it translates as 'ditch though Blu is a made up non name. Same for Kerr. Your child will get funny looks his whole life for those ones.