US Immigration from Peru

Hi all, I am going to need a financial sponsor to support my visa applications for my wife and stepdaughter. My father is willing to sponsor them and his finances are more than adequate, but I have a question about his age. My father is 84 years old. Does anyone know if age is a factor in judging the acceptability of a financial sponsor? Since he would be assuming responsibility for them for many years, I'm wondering if his age might be grounds for disqualifying him as a sponsor. I also have a close friend who is the same age as me (50) who would probably be willing to be a sponsor, but my preference would be to use my father. Any thoughts?

Can anyone tell me what kind of information (and in what format) should be included in this part of the I-130 application?