I am working on enhancements to a website of a not-for-profit organization. They have annual memberships with different kinds of memberships (single, family, junior, senior, etc.) being different prices.  Members have access to certain articles (club minutes, financial info, membership lists) that non-members don't have access to.I would like to integrate online payment for the memberships into the site registration process and have already added custom fields using the K2 extended user fields process (pretty easy to do).I still need some way to pay for the memberships though.  I tried a couple of subscription packages but really like AEC.  I asked AEC if it would be a problem but still don't have an answer.  I thought you guys might.  I've read the sections on the forum regarding AEC and K2 but they didn't answer this question.Any help you can give (the more specific the better) would be appreciated. TIA.