To help further clarify the whole "pick your 6 Pokemon" thing on the application, let me explain how Pokemon will be classified:
Pokemon Classifications
Basic Ex: Squirtle, Charmander, Bulbasaur
Stage I Ex: Wartortle, Charmeleon, Ivysaur
Stage II Ex: Blastoise, Charizard, Venusaur
You are allowed a maximum of one stage II and two stage ones at the start. So, as you can see...even though Snorlax is a "fully evolved Pokemon" because there is no evolution after him, he is a Stage I Pokemon still. So you could have say a Blastoise AND a Snorlax and it is within the rules because Blastoise is a Stage II Pokemon and Snorlax is a Stage I Pokemon.
Make sense? Hopefully this clarifies things. So for those of you with the Evee evolutions, you don't have to keep it an Evee unless you already have 2 other Stage I Pokemon because Vaporeon, Leafeon, or Umbreon classify as Stage I Pokemon since Evee comes before them and is the Basic Pokemon.