Steem itself doesn't have a really great place for this, at least using the native APIs. The way you're pulling from the @sn0n/profile permalink post is probably one of the best ways (using the json_metadata on that post, or even an account) unless you want to dig into creating custom_json transactions and then indexing them yourself with a database + api.

I don't really know of any good place with this sort of information unfortunately, or I'd direct ya there. Happy to answer questions though!