The forms from www.cic.gc.ca are fine.
When you sponsor an FC4 (parents, grandparents, other family members) your forms for the Principal Applicant are sent to you as part of the process, however they are the same forms found on the website.
When it asks for an "Original Form" it's requesting the one you originally filled out rather then a photocopy. This would be to confirm that the forms received will contain original signatures.
Best of luck...