You're quite welcome.
The adventure modules are not released 'in order', i.e., they vary from level to level with each new one published. And I have heard Joseph say that there will always be more lower level modules published than higher ones -- just market forces in play there.
Interesting that you found the subscription form... Are you part Elf?
Anyway, there used to be a subscription option for the modules back in the 3e days. I'm 99.783% sure it is defunct now. ...But who knows if it will come back next year for the new game...?
As for highly regarded boxed sets, Castle Whiterock is justly heaped with praise. The Gazeteer of the Known Realms has fans the world over. The others are compilations of popular modules... You really can't go wrong; it just depends on what grabs your interest most! Again, all of these were written for 3rd Edition D&D, but since DCC RPG is built on the same basic engine, the conversion can be done without fuss. The main tip: each level in DCC RPG is roughly equivalent to 2 levels in D&D, or so many have commented.