This may be a little late to help you out. There is a new market place that is doing a soft launch this week. It is called DUvisio.com. It is a similar platform to JVZoo in that it pays instant commissions. It does a lot of things different from JVZoo one being that it makes it extremely easy to do joint ventures.
You are having a problem of collecting the buyer information in both you and your partner's autoresponder. Well, DUvisio.com makes it possible for you and your partner to collect the buyer info in separate autoresponders.
As DUvisio.com is just launching, you would need to invite your own affiliates to join DUvisio.com to promote your product.
Making it easier to do joint ventures is only one of the things that differentiate DUvisio.com from all the other instant commission systems.
One other very big difference is that DUvisio.com prevents fraud from affiliates and vendors. All the other platforms do nothing to help prevent this fraud except to say not to approve any affiliates for instant commissions that you don't know.
At DUvisio.com vendors do not do the approving of affiliates. The software at DUvisio.com determines which affiliates will receive instant commission payments and which affiliates will receive delayed payments that will be paid automatically at 60 days after the sale. The system actually has PayPal determine which people will be allowed to become vendors and which people will be allowed to receive instant commission payments.
This means that affiliates don't have to have vendor approval to promote a vendor's product.
It even has a system to pay JV brokers a second tier instant commission making it possible to hire a JV Broker to help recruit affiliates to promote your products.
It allows digital, physical and service type products. It does a lot more that the other platforms. But, please remember it will be in beta for six months so there are bound to be an unforeseen glitch here or there.