Sponsoring B2 Visa in case of parents having more than 1 kid in US?

Hi,

I and my sister have been working in US at 2 different locations. I work for a desi consultant in H1B visa for the last 1 year and my sister work for a reputed top Indian IT company in L1B visa for the last 5 months. We would like to bring our parents to US who are in India on B2 Visa.

Question is do both of us need to send the following documents or either one of us is sufficient to apply for visa? If one, who is more appropriate to sponsor for visa?

Bank Account Verification letter
Affidavit of Support I-134 Form
Copies of W2 Form, Paystubs,
Invitation Letter
Visa officer Cover letter:

Please let me know all the finer points wrt my case.

TIA

Madhan

Anyone’s should work, good to have details of both in hand during interview.