Re: green card
If your parents are past 60 they should have no problem getting their GCs in 180 days from the time you submit the DS7 forms. Just find a good lawyer to handle the paperwork for you - a $ 200 expense at the most. Also, the Nebraska INS office processes paper faster than other ones. But then, if you go to a lawyer, he/she would advise you on that.
Hope your parents join you soon.