Why are you looking at Carbon Fibre bows? I think you'll find if you have pro ambitions that a CF bow will not do the job in terms of either tone or response. I have a nice Col Legno CF bow which I use mainly for outdoor gigs or for pieces where there's a lot of col legno playing (amazingly enough...). For everything else I use either my Andrew McGill bow (definitely no. 1) or my H.R. Pfretschner. In terms of length, all three are within 5mm overall, the CF bow and the McGill are 695mm overall (including button) and the Pfreschner is just under 700mm. They are all on the short side compared to what others in my section use, but it causes me no issues at all. Use what works, there are no rules.