I would never use Paypal for a launch, I have heard too many stories of funds being withheld for 6 months at a time. It happens when you have the type of activity a launch can bring.

I would definitely suggest you use a processor that is tried and tested for these types of product launches, such as Clickbank. The next step would be getting your own merchant account setup but that can be costly and time-consuming.

I can assure you that ringing them first doesn't make a difference. I don't recommend PayPal for product launches. Anything that is outside your normal pattern of sales will freak them out. Make too many sales in one day and bye bye PayPal and bye bye money, for a few months anyway.