correct. you need to set up a dns server, configure both forward and reverse lookups, and then enter that address in the tunnel setup webpage
The server you set up actually doesn't have to do forward lookups for your existing domain, or any forward domain really.
RDNS for your HE supplied IPv6 addresses are a completely different domain controlled by HE. They have the whole "0.7.4.0.220.127.116.11.ip6.arpa." RDNS domain delegated to them, since they own 2001:470::/32. They in turn delegate subdomains of that ip6.arpa for each /64 and/or /48 they assign to each user to the name servers each user specifies.
So all you have to do is stand up a DNS server which has the ip6.arpa for your network space as a zone and point HE to it via the web page. The name server doesn't even have to be in the same domain as your forward domain. It can be a completely separate deal. It just has to answer queries for your ip6.arpa subdomain which HE has delegated to it.
Of course, if he decided delegate the RDNS to a name server in his existing domain and add an IPv6 to one of his existing name servers, or add a new IPv6 speaking name server in the domain, he would then have to change his existing forward domain stuff and add whatever is needed. Looks like he has godaddy's servers doing DNS for "everettcoffee.com". AFAIK godaddy does allow you to add AAAA records, but I don't think their own name servers actually do IPv6 themselves, if that's a requirement (neither ns25 or ns26.domaincontrol.com [godaddy's servers delegated for "everettcoffee.com"] have AAAA records).