Careful with Cloudflare, they don't let you change nameservers[1]:

> Registrant agrees to use Cloudflare’s nameservers. REGISTRANT ACKNOWLEDGES AND AGREES THAT IT MAY NOT CHANGE THE NAMESERVERS ON THE REGISTRAR SERVICES, AND THAT IT MUST TRANSFER TO A THIRD PARTY REGISTRAR IF IT WISHES TO CHANGE NAMESERVERS.

So it's a no-go if you want to use Route 53 or something like that.

[1] https://www.cloudflare.com/domain-registration-agreement/