Will this work for me?

[jk]

Hello I am new to this community. I am a developer and I have a client that has a pretty small budget (go figure) that wants me to build a very simple site. I don't want to build it from scratch as I think there are probably options out there that will be much less costly. I am wondering if this shopping cart will be able to achieve this simple functionality:
1. he wants someone to enter a couple of values into a form (these values will be processed by a simple calculator php app)

2. the user will hit a checkout button, enter their CC information and hit submit

3. if the cc transaction is successful, they are returned some values based on the values entered in step 1

He doesn't want the user to have to login or create an account.

The key to this is storing the values, calling the php function and somehow returning the values after the transaction is finished. I am thinking on the receipt

Thanks for any help!