Adding Custom Checkout with Authorize.net

I would like to make a form on our WordPress website which allows us to place parameters on a purchase fulfilled by Authorize.net. By this, I mean that I want to be able to sell a ticket, and then have the user’s input of their name, meal choice, seat choice, and so on included in the purchase database. I would also like to send a customized email to the person afterward with all the details. Let’s say we want to process a donation as well. I’d like to take the user’s name, organization name, comments, and so on.

How do I do that? Is there a plugin which can do that for me? I have not found one yet which serves this need and I’ve been looking extensively.

What is the best way to do this? I’m even open to using plain PHP.

Thank you,
Brendan