Hi,
Yes it's possible, many ways for that, you can do a translation override or edit directly the view "product / show" and display this message.
I think that you will not have a common checkout, if it's the case thanks to enable the option "Catalog mode" in Configuration > Features. This will remove the add to cart buttons, then don't set any price to your products and do a translation override on the "FREE_PRICE" key. You can to enable the option to display the "contact us for more information" button.