Hi Marlon,

Since I'm not quite sure of what your level of coding expertise is, I'll try to answer appropriately. 

If you haven't already, read this post regarding digital download products:

http://www.markettheme.com/forum/presale-questions/can-use-this-for-digital-downloads/page-1

I also have to say that technical support regarding actual customization of your theme isn't provided (should you choose to branch off of the Market foundation).  There are just an infinate number of customization things that could be done — all with their own technical levels.

That said, I think what you're getting at is if Market COULD be used to do what you mention….  It could be modified to operate that way, but doesn't as is.

Here is a breakdown…

Radio buttons:

Market doesn't currently use radio buttons in it's product post display, but the page it uses to display products (single.php) does use typical HTML post functionality.  So, if you knew what you were doing — you could add radio buttons with values in the code, that would display the option to choose a license.  You'd probably have to set the radio button values to change the pricing value that was sent to Paypal.

Email:

Market won't send an email when a payment is made, but Paypal will.  I don't remember whether you can include a custom message within Paypal, but I think you may be able to.  To sell Market, we use e-junkie to help with our digital download fulfillment.  It's only $5 a month, and gives you a lot of control and extra security features.  It also sends an email that you can customize.

Thank you page:

After a product is purchased through Paypal, your visitor will be returned to your website to a page you designate.  By default, they will be sent back to your home page of your website, but you can change that by altering the Return URL code within single.php (one of the theme files).  I think Paypal also has a Return URL setting somewhere within their code, but I'm not exactly sure which one takes priority.  It can be done though.  This "thank you" page could offer your download password, which you can tie to a different WordPress page (using the built in WP password protect feature).

But, this method wouldn't be as secure as e-junkie.

Again, my recommendation is to use Market and e-junkie together.  E-junkie has better security functions for digital products, because users can't share direct URLs to the Download or Password areas.

I hope this makes sense.