I moved one domain name, vandenhout.com to epag because they were listed on the Sixxs faq: Which DNS Registrars allow me to add AAAA glue for my Domain Name Servers? and the price was right (comparable to my old registrar Dotster depending on dollar versus euro exchange rate). But, the support address answered they can't add an IPv6 address at the moment. I'm hoping to find out how soon that situation can be fixed as I explicitly asked about IPv6 glue records before opening an account with epag.
Update 2008-09-02: misunderstanding solved and I have my IPv6 glue records.