Membership vs Supporter for allowing Members to create a blog?

Hey All,

I'm working on a membership site for a client and I've got a question about how to best do one of the features of the site.

We are looking to create two different types of member for this site.

1) has access to all site features (buddypress groups, pages, classifieds, private messageing, etc.), except the creation or administration of their own blog (ie - membersite.testsite.com). This will be our basic membership and what most of the users will be doing.

2) Has all of the same privileges as the basic members, with the addition of being able to create and administer a blog on the site (ie - membersite.testsite.com)

My question is this: what's the best way to accomplish the above?

Should I create two membership levels - 1 for basic members that has all features minus the blog creation and 1 for advanced that has all feature including the blog creation, then let users pick one or the other?

Should I create two membership levels - 1 for the basic members that has all of the features minus the blog creation and 1 for advanced members that only enables the blog creation and the user signs up as a basic member, then upgrades to include the advanced membership if they want the blogging ability (so they'd have two levels)?

Or

Should I create 1 membership level and 1 Supporter level - create the basic membership level with access to all features minus blog creation and then allow users to create a blog via the supporter plugin? If this is the best option, how do i set that up so that the supporter and membership don't conflict - because all members will have to be at least a basic member and only some of them will need to upgrade to the blogging functionality.

Thanks for all your help!