Simple! All you need to do is setup a shopping cart or secure form handler and use that to collect your buyers info. Then once your buyer submits their order they will be redirected to a 'Order being Confirmed' page and thats when you get a email saying an order has been placed and you simple loggin to your admin of your shopping cart or gather the information from the secure form and manual input each order with 2checkout.com.
To keep you looking professional create a
client-email@address.com because you will need to enter in an email address for your client. Once you complete entering the user info and billing info and you receive your confirmation message from your merchant to the
client-email@address.com that you created you then can send your client their confirmation from you as your company. This will enable you to manually bill your clients when ever you need and 2checkout.com offers monthly and yearly recurring billing.
I hope any of this helps. Just a quick brain storm I had that would enable you to manually bill your clients without the hassle and expense of gateway software or terminals.
I have never done this method but I have know clients and other webmasters who needed to do this untill they had the budget to afford authorize.net.
Good luck and if I can be of any further help to you just PM me or email me via
jjersey@we-serv-u.net