How can I redirect specific products in a store?

I have a second store setup for members only. It is not a product but an investment so when they select the type of investment (barrel investment) and "add to cart" I need it to redirect to a different site (jotform) to authorize a bank transfer. 

If there is a better way, perhaps allowing them to add the "item/investment" to the cart and once they click "checkout" it will redirect them. 

I added the available barrels as a service. Any suggestions?

Hi,
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