Using external anycast dns for a couple of sites

Hi All, I have a server in the UK and have a few clients in USA, I'm using Keycdn for the images/css etc.. for these sites of which is great All the DNS queries are local to UK and I'm looking at using either cloudns or Dnsmadeeasy for their anycast dns service, this bring the dns server closer to clients My question is, do I just copy all the domain dns records from Cpanels dns and replicate them in the external provider and thats it? Should I do just the nameservers, or both? Confused a little, hopefully someone will point me in the right direction Regards Keith