Advice: What to use for a new site

Hello all,

I would like some advice on how to achieve te following using wordpress:

I am planning to start a new website. Besides articles I will be offering several small files (excel-pdf-…) which users can download after paying a small fee (2€-5€).

my question now is: What should i use to achieve this?

So far i have tried several plugins and two of them i like:
* WP Simple Paypal Shopping cart: Very nice, but it only has 1 Return URL, so this would be difficult with more than one downloadable file.
* WP e-Commerce Plugin: A very nice plugin which fits all my needs, but i need to upgrade my paypal account to premium in order to fill in the API code. Besides that i can’t tell the difference between the payment options available (Paypal Express Checkout; Paypal Payments Pro; Paypal Payments Standard; Paypal Payments Standard 2.0)

Since i’m new in this area I would also like to ask: Are there any other options i can use to achieve this or is the e-commerce plugin my best bet?

Thanks in advance for your suggestions/opinions.