Integration- Autoresponder, shopping cart, membership site and offline CRM

Hello All-

I could use some advice from some experienced warriors.

I am needing to integrate an Autoresponder, shopping cart, membership site and offline CRM. My company currently has thousands of customers from direct marketing offline, and we will continue those channels. We have a high end proprietary CRM (sql based) that integrates easily via api.

We generate 3,000 new opt-ins everyday. Customers fill out a form to receive more info about our service. (Name, address, City, state, zip, phone, email, sex, date of birth and we also get date/time stamp and IP). Currently we use these leads in our call center for outbound calling.

I need to upload the leads real time to an autoresponder and start them in an autoresponder series. At the same time, they will still go to the call center. We are selling an online membership, but I am not happy with our current membership software.

I need to have all up to date information housed in our offline crm so that we can effectively handle customer service calls, collections and the extensive reports that in our crm.

I have been considering
Auto responders-
Imnicamail, ContstantContact, OneShoppingCart, Premiumwebcart or InfusionSoft

Shopping cart-
OneShoppingCart, Infusionsoft, Premiumwebcart or Nanacast

Membership Software-
SocialSam, Infusionsoft, aMember or Nanacast

Any advice or guidance would be greatly appreciated. This is going to be a large project and I am not worried about cutting a corner to save a few pennies. Most importantly- at the end of the day, I need my systems communicating.

Thanks.

jerry