Shopping cart with recurring billing/subscriptions
I'm looking for an ecommerce solution which would allow me to sell products as a one-time purchase (like a regular web store) and based on a subscription. In the latter case, once a person signs up, they would receive our "product of the month" in the beginning of each month. The plans will vary, but this is the basic idea.
Now, there are good one-time purchase platforms (Zen Cart, CubeCart) as well as membership/recurring billing ones (aMember). What would you suggest for a combined platform, i.e. one-time purchases and subscriptions in one package? Do any of the major shopping carts support subscriptions like these?