One-off micropayment purchases of individual articles

Hi,

In my ideal world, I’d like to be able to combine an all-you-can-eat membership subscription with the ability to purchase individual articles. I was, for example, looking at Cleeng, which can use Paypal for Digital Goods. But I don’t see how I could really easily integrate Cleeng with Membership. So I’m wondering if you can recommend something related to WPMU Dev that would play nice with Membership so that I get a single screen where people can (1) purchase the individual article or (2) purchase a subscription. If they are logged in, they just see the article. If they are not logged in, they get the option of (1) or (2) above. Any suggestions?

Cordially,

Justin Long