Miriam,
I wrote about Project Learn a few months back:
http://phillyschoolsearch.com/2010/10/20/cooperative-education/ I
have not actually visited, but it sounds like a great place if you are
willing/interested in being an active participant in a school.
As far as not visiting charters and just completing lots of
applications and visiting later, that's fine. However, many schools
force you to show up to get an application and submit it, so you have
to visit informally anyway.
Len