Passing drop down data to paypal?

We are doing ticket sales for a show. I would like customers to be able to choose a date, and then to specify the number of adult, youth, and children's tickets they want. And then send them to paypal for payment. I made this all work using an standard dropdown field and pricing product fields. However, they paypal receipt did not end up reflecting the date (done in the dropdown) of the performance they had chosen. This is critical as people bring in their receipts as proof of what they purchased. The data was in the gravity forms entries, but this isn't sufficient, I need to get the date in the receipt.

I have read support forums and read documentation, but I'm not seeing how to do this. I don't want to specify it as an option on each ticket product type, because people will then have to select it multiple times. I'd prefer to pass it to paypal some other way. I'd also like to not hand code the drop down in a hook because I'd like novice users to be able to update this form in the future with new ticket dates.

This is so easy to do in paypal itself, that I feel I must be missing something rather basic. Thanks for any help you can provide.

This would be my ideal setup, and then I'd pass the date somehow to paypal so it shows up on a receipt.

http://woodburycommunitytheatre.org/newtest/

I'd try something else, if there's another way it would work. I've tried a bunch of things, but nothing I've tried accomplishes what I'm after. I have to do something in the next day or so, even if it is returning to paypal's code, which I'd rather not do. Ticket sales were live, and THEN we realized we didn't have the dates on receipts. Have loved GF for other things, and it would be so easy for my clients if I could resolve this issue.

Paypal accepts an item name, which you are apparently passing to them. If I could get some information on what variable you pass to them, and in a hook could read the data from the drop-down for the performance date and append it to the string you are passing to paypal for the product name, I'd have a solution.

Alternately, I wondered whether there was a way to combine a product and option, to accomplish what I'm after, but I couldn't figure out a way to do it like this.

Paypal's own interface allows for two drop-downs and then combines them when you add the item to the cart. So I would suspect that others might try to use Gravity Forms this way as well.