OpenCart Forms Spam Prevention

General information for the website: We sell cartoon images licenses online
Kind of development: Customization of existing website
Num. of web pages/modules: 1
Description of every page/module: Fix form security
Description of requirements/features: Fix form security
Extra services needed: Customization, Optimization, Security
Specific technologies required: ajax, css, html, javascript, jquery
Extra notes: URL: http://www.offthemark.com/System/2014-12-29

Brief: On all products page, see the form that appears when BOOKS option is selected from the pricing calculator. This form is sending massive amounts of spam even with the captcha.

I would like to remove the captcha all together and apply these alternatives for securing the form: http://jumping-duck.com/tutorial/securing-forms-without-captcha/

Once applied and tested I may apply this to all forms on site.