That is fairly easy. Simply link the order button to the info page and then have another button on the info page to go checkout.

Is it possible to create a static html page and include it with as div on the same page billing.php?. This is a single page without layout, Where I can remove the layout of a single page?
We need this page to obtain additional customer information, specifications and images
Thanks

It is possible to add a ajax form to upload file but we need remove all layout on single page, how?

If you can find billing.php in your directory, then you should be able to do almost anything with it. Be sure to do a complete backup of your site before you go into the core pages like that though. I once messed up a whole site on accident. Proceed with caution.

As I am not familiar with AJAX, I found this:
http://www.ajaxf1.com/tutorial/ajax-file-upload-tutorial.html...

You should be able to create a blank page and add the AJAX code to it. I am sure you will have to experiment. Just make sure you back up everything before you begin!!!

Thanks, but, how/where create a blank page without layouts?
I am newbie

Go to Dashboard - Full Sitemap. Then click on which ever page you want this new blank page filed under, I would suggest billing, if that is available. Then go and download a new theme called 960 Starter Theme. I found it just by doing a search for 'Blank Theme' in the marketplace. Install it. Then go back to the site map and click on the name of you new page. Select design and then choose full on the top row and 960 Starter Theme on the bottom row. If you have any more questions, feel free to ask!