Please, I need some help. I would like to invite my wife's grandparents.

[SuperVisa]

Hi,

I would like to invite my wife grandparents (they are 85 years old) for a visit for less than 6 months. I would like that they attend my wife's university graduation in Canada.
She has not seen her grandparents for over 10 years. Please if you can let me know how to go about it. Do I need to apply online, or they need to apply online? Also regarding the letter to submit as invitation letter, etc. if anyone has a sample can you please post here or email it to me at amparocanas@hotmail.com
I will financially support their travel, stay, insurance, medical etc... Also I will send my T4, Notice of Assessment and bank statements. Letter from my employer. Land property papers.

Her grandfather is retired( with no pension) and her grandmother is house wife. Do they need to submit any document to show their land papers?. They do not have any bank account, they just have a house and 5 children in their country.

Must I apply for a regular visitor visa or is better to apply for a Super Visa?

Thanks for the help...

Regards..